Method for producing an optical effect layer containing magnetic or magnetizable pigment particles and exhibiting one or more indicia - Patent Application 20070122997

Abstract

The present invention relates to the field of protection of security documents, such as banknotes and identity documents, against counterfeiting and illegal duplication. In particular, the present invention provides a method for producing an optical effect layer (OEL) exhibiting one or more indicia (x30) on a substrate (x20), the method comprising the steps of exposing a coating layer (x10) comprising non-spherical magnetic or magnetizable pigment particles to a magnetic field of a magnetic field generator in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles, applying a top coating composition on the coating layer (x10) in the form of the one or more indicia (x30), and at least partially curing the coating layer (x10) and the one or more indicia (x30) in a curing device (x50).

Description

Detailed Description of the Invention

[0001] [Field of the Invention]

[0001] The present invention relates to the field of magnetic field generating devices and methods for producing optical effect layers (OELs) containing magnetically oriented, non-spherical, magnetic or magnetizable pigment particles. In particular, the present invention provides a magnetic field generating device and method for magnetically orienting non-spherical, magnetic or magnetizable pigment particles in a coating layer to produce an OEL, and the use of said OELs for decorative purposes as well as for anti-counterfeiting measures for security documents or articles.

[0002] [Background of the invention]

[0002] The use of inks, compositions, coatings, or layers containing oriented magnetic or magnetizable pigment particles, in particular optically variable magnetic or magnetizable pigment particles, for the production of security elements, for example in the field of security documents, is known in the art. Coatings or layers containing oriented magnetic or magnetizable pigment particles are disclosed, for example, in U.S. Pat. Nos. 2,570,856; 3,676,273; 3,791,864; 5,630,877; and 5,364,689. Coatings or layers containing oriented magnetic color-shifting pigment particles, which provide particularly attractive optical effects and help protect security documents, are disclosed in WO 2002 / 090002 and WO 2005 / 002866.

[0003] For example, security features for security documents can generally be classified as "covert" security features, on the one hand, and "overt" security features, on the other hand. The protection afforded by covert security features relies on the principle that such features are difficult to detect, typically requiring specialized equipment and knowledge for detection, while "overt" security features rely on the concept of being easily detectable by unaided human senses; for example, such features may be visible and / or detectable by touch, while remaining difficult to create and / or replicate. However, the effectiveness of overt security features depends significantly on their easy recognition as security features.

[0004]

[0004] Magnetic or magnetizable pigment particles in printing inks or coatings allow for the creation of magnetically inductive images, designs and / or patterns by the application of a correspondingly configured magnetic field, causing local orientation of the magnetic or magnetizable pigment particles in the unsolidified (i.e., wet) coating, followed by solidification of the coating. The result is a fixed, stable magnetically inductive image, design, or pattern. Materials and techniques for the orientation of magnetic or magnetizable pigment particles in coating compositions are disclosed, for example, in U.S. Pat. No. 2,418,479; U.S. Pat. No. 2,570,856; U.S. Pat. No. 3,791,864, DE 2006848 A1, U.S. Pat. No. 3,676,273, U.S. Pat. No. 5,364,689, U.S. Pat. No. 6,103,361, EP 0406667; U.S. Pat. Appl. Publ. No. 2002 / 0160194; U.S. Pat. Appl. Publ. No. 2004 / 0009309; EP 0710508; WO 2002 / 09002; WO 2003 / 000801; WO 2005 / 002866; WO 2006 / 061301. Such a method makes it possible to create magnetic induction patterns that are highly resistant to counterfeiting.The security element in question can only be created by having access to both magnetic or magnetizable pigment particles or corresponding pigment inks and the specific technology used to print said inks and to orient said pigments in the printed inks.

[0005]

[0005] In order to protect security documents or articles containing magnetically inductive images from the premature detrimental effects of soil and / or moisture over time and use, a protective varnish is conventionally applied as a continuous layer over an already prepared, dried / cured magnetically inductive image.

[0006]

[0006] WO 2011 / 012520 discloses a transfer foil comprising a coating layer in the form of a design, the design comprising oriented optically variable magnetic pigments representing an image, indicia, or pattern. The transfer foil may further comprise a top coating layer, the top coating layer being applied before the application of the layer comprising the optically variable magnetic pigment. The process for producing the transfer foil comprises the steps of: a) applying a top coating layer and hardening / curing the top coating layer; and b) applying a layer comprising the optically variable magnetic pigment, magnetically orienting the particles, and hardening / curing the layer. The disclosed method is not suitable for producing magnetically inductive images required to represent personalized variable indicia.

[0007]

[0007] EP 1641624, EP 1937415, and EP 2155498 disclose apparatus and methods for magnetically transferring indicia to unsolidified (i.e., wet) coating compositions containing magnetic or magnetizable pigment particles to form optical effect layers (OELs). The disclosed methods enable the production of security documents and articles with customer-specific magnetic designs. However, the disclosed magnetic devices are tailored to meet customer-specific magnetic designs and cannot be altered if the design needs to change from one article to another; therefore, the methods are not suitable for producing OELs required to display personalized variable indicia.

[0008] EP 3170566, EP 3459758, EP 2542421 and WO 2020 / 148076 disclose different methods for the creation of variable indicia in optically variable magnetic inks, but the methods require the use of special equipment such as photomasks, lasers or addressable LEDs.

[0009]

[0009] In order to provide variable information with magnetic properties on security documents or articles, inkjet inks containing magnetic particles have been developed to enable magnetic ink character recognition (MICR). However, these inkjet inks face various problems, particularly those related to the ink's shelf life stability, ink printability, non-uniform magnetic ink deposits, and printhead clogging. European Patent No. 2223976 discloses a method for producing documents containing MICR features, comprising the steps of inkjet printing a pattern of curable ink containing a gelling agent onto a substrate, cooling the ink to a temperature below the ink's gelling temperature, applying a magnetic material to the ink, and finally curing the ink. Alternatively, toners containing magnetic particles have also been developed, as disclosed, for example, in U.S. Pat. Nos. 10,503,091 and 10,359,730. However, specific dedicated equipment is required to print these toners.

[0010]

[0010] Therefore, there is a need for a method for universally producing customized optical effect layers exhibiting one or more indicia on an industrial scale, wherein the optical effect layers exhibit noticeable effects. Furthermore, the method should be reliable, simple to implement, and capable of functioning at high production rates.

[0011] [Summary of the Invention]

[0011] The present invention therefore aims to overcome the deficiencies of the prior art by providing a method for producing an optical effect layer (OEL), said OEL comprising a motif consisting of at least two areas of a single applied and cured layer containing non-spherical magnetic or magnetisable pigment particles and exhibiting one or more indicia (x30) on a substrate (x20), the method comprising: a) applying a radiation-curable coating composition on a surface of a substrate (x20) comprising a mixture of non-spherical magnetic or magnetizable pigment particles, one or more cationically curable compounds, one or more radiation-curable compounds, and a photoreactive compound that does not absorb in the range of about 350 nm to about 470 nm, wherein the radiation-curable coating composition is in a first liquid state to form a coating layer (x10); b) after step a), at least partially applying a top coating composition onto the coating layer (x10), thus forming one or more areas of the coating layer (x10) below said one or more indicia (x30), said top coating composition being applied in the form of one or more indicia (x30), said top coating composition comprising one or more curable compounds and a mixture of compounds, at least one of said compounds absorbing in the range of about 350 nm to about 470 nm; c) partially simultaneously with or after step b), at least partially curing one or more indicia (x30) and one or more areas of the coating layer (x10) below said one or more indicia (x30) with LED curing units (x50) emitting between 350 nm and 470 nm; d) after step c), exposing the coating layer (x10) to a magnetic field of a magnetic field generator in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; e) partially simultaneously with or after step d), at least partially curing the coating layer (x10) in curing units (x60) emitting at least between 250 nm and 320 nm, The method, wherein the mixture of photoreactive compounds of the radiation-curable coating composition of step a) and the mixture of compounds of the top-curable coating composition of step b) are selected according to one of the following combinations: i) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts and one or more α-hydroxyketone compounds; The mixture of compounds of step b) the top curable coating composition is i-1) The anion part is SbF6 - ;PF6 - ;AsF6 - ;F4B - ;(C6F5)4B - ;(CF3SO2)3C - ;(CF3)SO3 - ;(CH3C6H4)SO3 - ;(CF3)CO2 - ;(C4F9)SO3 - or (C4F9)CO2 - and the cationic moiety comprises one or more sulfonium salts which are tris[4-(4-acetylphenylsulfanyl)phenyl]sulfonium; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium; (9-oxo-9H-thioxanthen-2-yl)diphenylsulfonium; or mixtures thereof, and further comprises one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or benzyl ketal compounds and / or one or more oxime ester compounds, wherein the cationic moiety is 2,2-dimethoxy-1,2-diphenylethan-1-one; i-2) one or more thioxanthone compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; i-3) one or more anthracene compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; i-4) one or more naphthalene compounds and one or more anthracene compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or i-5) one or more coumarin compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds; or ii) the mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts and a benzyl ketal compound that is 2,2-diethoxyacetophenone; The mixture of compounds of step b) the top curable coating composition is ii-1) The anion part is SbF6 - ;PF6 - ;AsF6 - ;F4B - ;(C6F5)4B - ;(CF3SO2)3C - ;(CF3)SO3 - ;(CH3C6H4)SO3 - ;(CF3)CO2 - ;(C4F9)SO3 - or (C4F9)CO2 -and the cationic moiety comprises one or more sulfonium salts which are tris[4-(4-acetylphenylsulfanyl)phenyl]sulfonium; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium; (9-oxo-9H-thioxanthen-2-yl)diphenylsulfonium; or mixtures thereof, and further comprises one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or benzyl ketal compounds and / or one or more oxime ester compounds, wherein the cationic moiety is 2,2-dimethoxy-1,2-diphenylethan-1-one; ii-2) one or more thioxanthone compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; ii-3) one or more anthracene compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; ii-4) one or more naphthalene compounds and one or more anthracene compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; ii-5) one or more coumarin compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds; or iii) The mixture of photoreactive compounds of the radiation curable coating composition of step a) is a compound having an anionic moiety of SbF6 - ;PF6- ; AsF6 - ; F4B - ; (C6F5)4B - ; (CF3SO2)3C - ; (CF3)SO3 - ; (CH3C6H4)SO3 - ; (CF3)CO2 - ; (C4F9)SO3 - or (C4F9)CO2 -and the cationic moiety is 4-(phenylthio)phenyldiphenyl-sulfonium; bis[4-(diphenylsulfonium)phenyl]sulfide; (4-methylphenyl)diphenyl-sulfonium; (3-methylphenyl)diphenyl-sulfonium; bis(4-methylphenyl)phenyl-sulfonium; [(4-(1,1-dimethylethyl)phenyl]diphenyl-sulfonium; bis[4-(1-methylethyl)phenyl]phenyl-sulfonium; [(4-(2-methylpropyl)phenyl]diphenyl-sulfonium; (4-methoxyphenyl)diphenyl-sulfonium (4-phenyl)diphenyl-sulfonium;1-naphthalenyldiphenyl-sulfonium;Tris(4-methylphenyl)-sulfonium;(4-bromophenyl)diphenyl-sulfonium;(4-iodophenyl)diphenyl-sulfonium;(4-fluorophenyl)diphenyl-sulfonium;(4-chlorophenyl)diphenyl-sulfonium;(4-phenoxyphenyl)diphenyl-sulfonium;(4'-methyl[1,1'-biphenyl]-4-yl)diphenyl-sulfonium;Tris(4-propylphenyl)-sulfonium; Bis(4-butylphenyl)phenyl-sulfonium;Tris[4(1-methylethyl)phenyl]-sulfonium;S,S'-1,3-phenylenebis[S,S'-diphenyl]-sulfonium;(4-dodecylphenyl)diphenyl-sulfonium;(4-benzoylphenyl)diphenyl-sulfonium;Bis([1,1'-biphenyl]-4-yl)(4-methylphenyl)-sulfonium;Tris[4-[1,1-dimethylethyl)phenyl]-sulfonium;Triphenyl-sulfonium;5-(4-methylphenyl)-dibenzothio Phenium;5-[4-(2-hydroxyethoxy)phenyl]-thianthrenium;10-(4-methylphenyl)-9H-thioxanthenium;Diphenyl[4-[[(4-phenylthiophenyl]thio]phenyl]-sulfonium;Phenyl-bis[4-phenylthio)phenyl]-sulfonium;5-[4-(phenylthio)phenyl]-thianthrenium;5-[4-(phenylthio)phenyl]-dibenzothiophenium;10-[4-(diphenylthio)phenyl]-9H-thioxanthenium;5-Phenyl-thianthrenium;10-phenyl-9H-thioxanthenium; 5-(4-methylphenyl)-thianthrenium; 5-[1,1'-biphenyl]-4-yl-thianthrenium; S,S'-(thiodi-4,1-phenylene)bis[S,S'-bis[4-(2-hydroxyethoxy)]phenyl]-sulfonium; or mixtures thereof, comprising one or more sulfonium salts, and one or more α-hydroxyketone compounds; The mixture of compounds of step b) the top curable coating composition is iii-1) one or more sulfonium salts listed in i-1), and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds; iii-2) one or more thioxanthone compounds and one or more iodonium salts, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds; iii-3) one or more anthracene compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; iii-4) one or more naphthalene compounds and one or more anthracene compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or iii-5) one or more coumarin compounds and one or more iodonium salts, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds; or iv) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts listed in iii) and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds of step b) the top curable coating composition is iv-1) one or more sulfonium salts listed in i-1), and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds; iv-2) one or more thioxanthone compounds and one or more iodonium salts, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds; iv-3) one or more anthracene compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; iv-4) one or more naphthalene compounds and one or more anthracene compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or iv-5) one or more coumarin compounds and one or more iodonium salts, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds; or v) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts and one or more α-hydroxyketone compounds; and The mixture of compounds of step b) the top curable coating composition is v-1) one or more sulfonium salts listed under i-1); v-2) one or more thioxanthone compounds; v-3) one or more anthracene compounds; v-4) one or more naphthalene compounds and one or more anthracene compounds; or v-5) containing one or more coumarin compounds; or vi) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more of an iodonium salt and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds of step b) the top curable coating composition is vi-1) one or more sulfonium salts listed under i-1); vi-2) one or more thioxanthone compounds; vi-3) one or more anthracene compounds; vi-4) one or more naphthalene compounds and one or more anthracene compounds; or vi-5) containing one or more coumarin compounds; or vii) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more of the sulfonium salts listed in iii) and one or more α-hydroxyketone compounds; and The mixture of compounds of step b) the top curable coating composition is vii-1) one or more sulfonium salts listed under i-1); vii-2) one or more thioxanthone compounds and one or more iodonium salts; vii-3) one or more anthracene compounds; vii-4) one or more naphthalene compounds and one or more anthracene compounds; or vii-5) containing one or more coumarin compounds and one or more iodonium salts; or viii) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more of the sulfonium salts listed in iii) and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds of step b) the top curable coating composition is viii-1) one or more sulfonium salts listed under i-1); viii-2) one or more thioxanthone compounds and one or more iodonium salts; viii-3) one or more anthracene compounds; viii-4) one or more naphthalene compounds and one or more anthracene compounds; or viii-5) One or more coumarin compounds and one or more iodonium salts This is achieved by providing:

[0012] A summary of the eight embodiments i) to viii) and preferred ones is provided below in the table entitled "Summary of the first to eighth embodiments described herein."

[0013] A list of compounds and preferences for the radiation curable coating composition of step a) and the top curable coating composition of step b) is provided in Tables T1 to T11.

[0014] In one preferred embodiment, step a) of applying the radiation curable coating composition is carried out by a process selected from the group consisting of screen printing, gravure printing, pad printing, and flexographic printing.

[0015] In one preferred embodiment, step b) of applying the top coating composition is carried out by a non-contact fluid micro-dispensing technique, preferably an inkjet printing process.

[0016]

[0016] Also described herein are optical effect layers (OELs) and security documents made by the methods described herein, as well as decorative elements and decorative objects comprising one or more optical OELs described herein.

[0017]

[0017] Also described is a method for producing a security document, or a decorative element or decorative body, the method comprising: a) providing a security document, or a decorative element or decorative body, and b) providing an optical effect layer, such as those described in the present specification, in particular those obtained by the method described in the present specification, which is included by the security document or decorative element or decorative body.

[0018]

[0018] The method described herein advantageously allows for the production of an optical effect layer (OEL) consisting of a single layer and comprising two or more areas of a radiation-curable coating composition comprising non-spherical magnetic or magnetizable pigment particles, said two or more areas comprising non-spherical magnetic or magnetizable pigment particles oriented according to different orientation patterns with high resolution, said method not requiring the use of a photomask or a curing unit equipped with a laser or an addressable LED curing unit.

[0019] The method advantageously described herein uses two compositions, which are applied to one another in a wet-on-wet state. In particular, the method according to the invention allows the production of optical effect layers (OELs) universally exhibiting one or more indicia and can be easily carried out on an industrial scale at high production rates. The two compositions used in the method described herein comprise, as a first composition, a radiation-curable coating composition comprising non-spherical magnetic or magnetizable pigment particles, which is applied onto a substrate (x20), and as a second composition, a top-coating composition, which is applied at least partially onto the radiation-curable coating composition comprising the pigment particles and partially overlaps (i.e., overlaps in at least one area) said composition when the radiation-curable coating composition is still in a wet, unpolymerized state, and is applied in the form of one or more indicia.

[0020]

[0020] The present invention provides a reliable and easy to implement method for producing high-visibility optical effect layers (OELs) exhibiting one or more indicia as described herein. The disclosed method advantageously enables the production of security documents and articles with customer-specific magnetic designs that also exhibit one or more indicia in an easy to implement and highly reliable manner with generic online variation, without requiring customization of magnet assemblies used to orient non-spherical magnetic or magnetizable pigment particles for each variable or individualized indicia and for each and every customer-specific optical effect layer (OEL), and without requiring the use of solidification units with photomasks or addressable LED curing units.

[0021]

[0021] The method described herein for producing an optical effect layer (OEL) exhibiting one or more marks (x30) on a substrate (x20) described herein is described in more detail below with reference to the drawings and specific embodiments. FIG. 1 illustrates diagrammatically non-spherical, in particular platelet-shaped, pigment particles. 2A-2K illustrate a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, in particular: 2A-1 and 2A-2 schematically illustrate a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention. The method comprises the steps of: b) at least partially applying a top-coating composition onto a coating layer (210), said top-coating composition being applied in the form of one or more indicia (230); c) after step b) at least partially curing the one or more indicia (230) and one or more areas of the coating layer (210) below said one or more indicia (230) with an LED curing unit (250); d) after step c) still remaining portions of the coating layer (210) The method includes step d) of exposing the coating layer (210) to a magnetic field of a magnetic field generator (B1) to uniaxially orient (2A-1) or biaxially orient (2A-2) at least a portion of the non-spherical magnetic or magnetizable pigment particles in the uncured areas; and step e) of at least partially curing the coating layer (210) in a curing unit (260) emitting at least radiation between 250 nm and 320 nm, partially simultaneously with step d) (Figure 2A-1) or after step d) (Figure 2A-2). 2B illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention. The method comprises the steps of: applying a top-coating composition on the coating layer (210), said top-coating composition being applied in the form of one or more indicia (230); after step b), exposing the coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; partially simultaneously with the orienting step, maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210) while aligning the one or more indicia (230) and the coating under the one or more indicia (230). The method includes step c) of at least partially curing one or more areas of the layer (210) in an LED curing unit (250); step d) after step c) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) to orient at least a portion of the magnetic or magnetizable pigment particles in the as-yet-uncured areas of the coating layer (210); and step e) partially simultaneously with step d) of at least partially curing the coating layer (210) in an Hg curing unit (260) while maintaining the magnetic field generator (B2) in the vicinity of the coating layer (210). 2C illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; b) partially simultaneously with the step of applying a top coating composition on the coating layer (210), the top coating composition being applied in the form of one or more indicia (230) while maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210); and after step b), removing the one or more indicia (230) and the coating under the one or more indicia (230) while maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210). The method includes step c) of at least partially curing one or more areas of the coating layer (210) in an LED curing unit (250); step d) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) after step c) in order to orient at least a portion of the magnetic or magnetizable pigment particles in the as-yet-uncured areas of the coating layer (210); and step e) of at least partially curing the coating layer (210) in a curing unit (260) emitting at least between 250 nm and 320 nm while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210) partially simultaneously with step d). 2D illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; b) partially simultaneously applying a top-coating composition onto the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230) while maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210); c) after step b), at least partially curing the one or more indicia (230) and one or more areas of the coating layer (210) below the one or more indicia (230) with an LED curing unit (250) while maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210); The method includes a step d) after step c), of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210) in a biaxial direction; a step after said step of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) in order to orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210); and a step e) partially simultaneously with said step, of at least partially curing the coating layer (210) in a curing unit (260) radiating at least between 250 nm and 320 nm while maintaining the magnetic field generator (B3) in the vicinity of the coating layer (210). 2E illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to biaxially orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step, applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), curing the one or more indicia (230) and one or more areas of the coating layer (210) below the one or more indicia (230) with an LED curing unit (250). the step c) of at least partially curing; the step d) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) after step c) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the as-yet-uncured areas of the coating layer (210); and the step e) of at least partially curing the coating layer (210) in a curing unit (260) radiating at least between 250 nm and 320 nm while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210), partially simultaneously with step d). 2F and 2G illustrate a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to biaxially orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after step b), applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; and, partially simultaneously with step b), applying one or more indicia while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210). The method includes step c) of at least partially curing the indicia (230) and one or more areas of the coating layer (210) below the one or more indicia (230) in an LED curing unit (250); step d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) after step c) to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210); and step e) of at least partially curing the coating layer (x10) in a curing unit (260) emitting at least light between 250 nm and 320 nm, partially simultaneously with step d) (Figure 2F) or after step d) (Figure 2G). 2H and 2I illustrate a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention. The method comprises the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to biaxially orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step b), applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step, applying one or more indicia (x30) and the one or more indicia (x30) to the magnetic field of a second magnetic field generator (B3). The method includes step c) of at least partially curing one or more areas of the coating layer (210) under the coating layer (230) with an LED curing unit (250); step d) after step c) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the as-yet-uncured areas of the coating layer (210); and step e) of at least partially curing the coating layer (x10) with a curing unit (260) emitting at least light between 250 nm and 320 nm, either partially simultaneously with step d) (Figure 2H) or after step d) (Figure 2I). 2J illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in a biaxial direction; after said step, exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; and partially simultaneously with said step, a step b) of applying a top coating composition onto the coating layer (210), the top coating composition being applied in the form of one or more indicia (230) while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210); after step b), maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210). the step (c) of at least partially curing the one or more indicia (230) and one or more areas of the coating layer (210) beneath said one or more indicia (230) in an LED curing unit (250) while maintaining said one or more indicia (230); the step (d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) after step (c) to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the as-yet uncured areas of the coating layer (210); and the step (e) of at least partially curing the coating layer (x10) in a curing unit (260) radiating at least between 250 nm and 320 nm while maintaining the third magnetic field generator (B3) in the vicinity of the coating layer (210) partially simultaneously with step (d). 2K illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in a biaxial direction; after said step, exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step, a step b) of applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), applying one or more indicia (x30) and a top-coating composition under the one or more indicia (230). the step (c) of at least partially curing one or more areas of the coating layer (210) in an LED curing unit (250); after step (c), step (d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the as-yet uncured areas of the coating layer (210); and partially simultaneously with step (d), step (e) of at least partially curing the coating layer (x10) in a curing unit (260) emitting at least between 250 nm and 320 nm while maintaining the third magnetic field generator (B3) in the vicinity of the coating layer (210). 3A-B schematically illustrate a magnetic field generating device for biaxially (FIG. 3A) or uniaxially (FIG. 3B) orienting magnetic or magnetizable pigment particles in a coating layer (310) on a substrate (320). 4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165). [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 illustrates diagrammatically non-spherical, in particular platelet-shaped, pigment particles. [Figure 2A-1]2A-1 and 2A-2 schematically illustrate a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention. The method comprises the steps of: b) at least partially applying a top-coating composition onto a coating layer (210), said top-coating composition being applied in the form of one or more indicia (230); c) after step b) at least partially curing the one or more indicia (230) and one or more areas of the coating layer (210) below said one or more indicia (230) with an LED curing unit (250); d) after step c) still remaining portions of the coating layer (210) The method includes step d) of exposing the coating layer (210) to a magnetic field of a magnetic field generator (B1) to uniaxially orient (2A-1) or biaxially orient (2A-2) at least a portion of the non-spherical magnetic or magnetizable pigment particles in the uncured areas; and step e) of at least partially curing the coating layer (210) in a curing unit (260) emitting at least radiation between 250 nm and 320 nm, partially simultaneously with step d) (Figure 2A-1) or after step d) (Figure 2A-2). [Figure 2A-2]2A-1 and 2A-2 schematically illustrate a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention. The method comprises the steps of: b) at least partially applying a top-coating composition onto a coating layer (210), said top-coating composition being applied in the form of one or more indicia (230); c) after step b) at least partially curing the one or more indicia (230) and one or more areas of the coating layer (210) below said one or more indicia (230) with an LED curing unit (250); d) after step c) still remaining portions of the coating layer (210) The method includes step d) of exposing the coating layer (210) to a magnetic field of a magnetic field generator (B1) to uniaxially orient (2A-1) or biaxially orient (2A-2) at least a portion of the non-spherical magnetic or magnetizable pigment particles in the uncured areas; and step e) of at least partially curing the coating layer (210) in a curing unit (260) emitting at least radiation between 250 nm and 320 nm, partially simultaneously with step d) (Figure 2A-1) or after step d) (Figure 2A-2). [Figure 2B]2B illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention. The method comprises the steps of: applying a top-coating composition on the coating layer (210), said top-coating composition being applied in the form of one or more indicia (230); after step b), exposing the coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; partially simultaneously with the orienting step, maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210) while aligning the one or more indicia (230) and the coating under the one or more indicia (230). The method includes step c) of at least partially curing one or more areas of the layer (210) in an LED curing unit (250); step d) after step c) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) to orient at least a portion of the magnetic or magnetizable pigment particles in the as-yet-uncured areas of the coating layer (210); and step e) partially simultaneously with step d) of at least partially curing the coating layer (210) in an Hg curing unit (260) while maintaining the magnetic field generator (B2) in the vicinity of the coating layer (210). [Figure 2C]2C illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; b) partially simultaneously with the step of applying a top coating composition on the coating layer (210), the top coating composition being applied in the form of one or more indicia (230) while maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210); and after step b), removing the one or more indicia (230) and the coating under the one or more indicia (230) while maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210). The method includes step c) of at least partially curing one or more areas of the coating layer (210) in an LED curing unit (250); step d) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) after step c) in order to orient at least a portion of the magnetic or magnetizable pigment particles in the as-yet-uncured areas of the coating layer (210); and step e) of at least partially curing the coating layer (210) in a curing unit (260) emitting at least between 250 nm and 320 nm while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210) partially simultaneously with step d). [Figure 2D]2D illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; b) partially simultaneously applying a top-coating composition onto the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230) while maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210); c) after step b), at least partially curing the one or more indicia (230) and one or more areas of the coating layer (210) below the one or more indicia (230) with an LED curing unit (250) while maintaining the magnetic field generator (B1) in the vicinity of the coating layer (210); The method includes a step d) after step c), of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210) in a biaxial direction; a step after said step of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) in order to orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210); and a step e) partially simultaneously with said step, of at least partially curing the coating layer (210) in a curing unit (260) radiating at least between 250 nm and 320 nm while maintaining the magnetic field generator (B3) in the vicinity of the coating layer (210). [Figure 2E]2E illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to biaxially orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step, applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), curing the one or more indicia (230) and one or more areas of the coating layer (210) below the one or more indicia (230) with an LED curing unit (250). the step c) of at least partially curing; the step d) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) after step c) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the as-yet-uncured areas of the coating layer (210); and the step e) of at least partially curing the coating layer (210) in a curing unit (260) radiating at least between 250 nm and 320 nm while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210), partially simultaneously with step d). [Figure 2F]2F and 2G illustrate a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to biaxially orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after step b), applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; and, partially simultaneously with step b), applying one or more indicia while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210). The method includes step c) of at least partially curing the indicia (230) and one or more areas of the coating layer (210) below the one or more indicia (230) in an LED curing unit (250); step d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) after step c) to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210); and step e) of at least partially curing the coating layer (x10) in a curing unit (260) emitting at least light between 250 nm and 320 nm, partially simultaneously with step d) (Figure 2F) or after step d) (Figure 2G). [Figure 2G]2F and 2G illustrate a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to biaxially orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after step b), applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; and, partially simultaneously with step b), applying one or more indicia while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210). The method includes step c) of at least partially curing the indicia (230) and one or more areas of the coating layer (210) below the one or more indicia (230) in an LED curing unit (250); step d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) after step c) to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210); and step e) of at least partially curing the coating layer (x10) in a curing unit (260) emitting at least light between 250 nm and 320 nm, partially simultaneously with step d) (Figure 2F) or after step d) (Figure 2G). [Figure 2H]2H and 2I illustrate a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention. The method comprises the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to biaxially orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step b), applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step, applying one or more indicia (x30) and the one or more indicia (x30) to the magnetic field of a second magnetic field generator (B3). The method includes step c) of at least partially curing one or more areas of the coating layer (210) under the coating layer (230) with an LED curing unit (250); step d) after step c) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the as-yet-uncured areas of the coating layer (210); and step e) of at least partially curing the coating layer (x10) with a curing unit (260) emitting at least light between 250 nm and 320 nm, either partially simultaneously with step d) (Figure 2H) or after step d) (Figure 2I). [Figure 2I]2H and 2I illustrate a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention. The method comprises the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to biaxially orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step b), applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step, applying one or more indicia (x30) and the one or more indicia (x30) to the magnetic field of a second magnetic field generator (B3). The method includes step c) of at least partially curing one or more areas of the coating layer (210) under the coating layer (230) with an LED curing unit (250); step d) after step c) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the as-yet-uncured areas of the coating layer (210); and step e) of at least partially curing the coating layer (x10) with a curing unit (260) emitting at least light between 250 nm and 320 nm, either partially simultaneously with step d) (Figure 2H) or after step d) (Figure 2I). [Figure 2J]2J illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in a biaxial direction; after said step, exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; and partially simultaneously with said step, a step b) of applying a top coating composition onto the coating layer (210), the top coating composition being applied in the form of one or more indicia (230) while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210); after step b), maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210). the step (c) of at least partially curing the one or more indicia (230) and one or more areas of the coating layer (210) beneath said one or more indicia (230) in an LED curing unit (250) while maintaining said one or more indicia (230); the step (d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) after step (c) to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the as-yet uncured areas of the coating layer (210); and the step (e) of at least partially curing the coating layer (x10) in a curing unit (260) radiating at least between 250 nm and 320 nm while maintaining the third magnetic field generator (B3) in the vicinity of the coating layer (210) partially simultaneously with step (d). [Figure 2K]2K illustrates a schematic diagram of a method for producing an optical effect layer (OEL) on a substrate (220) according to the present invention, comprising the steps of: exposing a coating layer (210) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in a biaxial direction; after said step, exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; after said step, a step b) of applying a top-coating composition on the coating layer (210), the top-coating composition being applied in the form of one or more indicia (230); after step b), applying one or more indicia (x30) and a top-coating composition under the one or more indicia (230). the step (c) of at least partially curing one or more areas of the coating layer (210) in an LED curing unit (250); after step (c), step (d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3) in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles in the as-yet uncured areas of the coating layer (210); and partially simultaneously with step (d), step (e) of at least partially curing the coating layer (x10) in a curing unit (260) emitting at least between 250 nm and 320 nm while maintaining the third magnetic field generator (B3) in the vicinity of the coating layer (210). [Figure 3A] 3A-B schematically illustrate a magnetic field generating device for biaxially (FIG. 3A) or uniaxially (FIG. 3B) orienting magnetic or magnetizable pigment particles in a coating layer (310) on a substrate (320). [Figure 3B] 3A-B schematically illustrate a magnetic field generating device for biaxially (FIG. 3A) or uniaxially (FIG. 3B) orienting magnetic or magnetizable pigment particles in a coating layer (310) on a substrate (320). [Figure 4A] 4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165). [Figure 4B]4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165). [Figure 4C] 4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165). [Figure 4D] 4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165). [Figure 4E] 4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165). [Figure 4F] 4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165). [Figure 4G] 4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165). [Figure 4H] 4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165). [Figure 5] 4A-H and FIG. 5 show photographs of OELs prepared by the method according to the present invention (E1-E165).

[0023] [Detailed explanation] definition The following definitions are discussed in the detailed description and are used to interpret the meaning of terms recited in the claims.

[0024]

[0023] As used herein, the term "at least one" is meant to define one or more than one, for example, 1, 2, or 3.

[0025]

[0024] As used herein, the terms "about" and "substantially" mean that the amount or value in question is a specified specific value or some other value in its vicinity. Generally, the terms "about" and "substantially," which indicate a value, are intended to indicate a range of ±5% of the value. As an example, the expression "about 100" indicates a range of 100 ±5, i.e., a range of 95 to 105. Generally, when the terms "about" and "substantially" are used, it can be expected that similar results or effects of the present invention can be obtained within a range of ±5% of the indicated value.

[0026] The term "substantially parallel" refers to a deviation of 10 degrees or less from a parallel alignment, and the term "substantially perpendicular" refers to a deviation of 10 degrees or less from a perpendicular alignment.

[0027]

[0026] As used herein, the term "and / or" means that all or only one of the elements of the group may be present. For example, "A and / or B" shall mean "A only, or B only, or both A and B." In the case of "A only," the term also encompasses the possibility that B is absent, i.e., "A only and no B."

[0028] The term "comprising" as used herein is meant to be non-exclusive and non-limiting. Thus, for example, a coating composition comprising compound A may contain other compounds in addition to A. However, the term "comprising" also encompasses the more restrictive meanings of "consisting essentially of" and "consisting of," as specific embodiments thereof, so that, for example, "a fountain solution comprising A, B, and optionally C" may also consist (substantially) of A and B, or (substantially) of A, B, and C.

[0029]

[0028] As used herein, the term "optical effect layer" (OEL) refers to a coating layer comprising oriented magnetic or magnetizable pigment particles, which are oriented by a magnetic field, and which are fixed / frozen in their orientation and position and solidified (i.e., after curing) to form a magnetically induced image.

[0030] The term "coating composition" refers to any composition capable of forming an optical effect layer (OEL) on a solid substrate, preferably, but not exclusively, applied by a printing method. The coating composition comprises the non-spherical magnetic or magnetizable pigment particles described herein and the binder described herein. The term "top coating composition" refers to a composition that does not contain the non-spherical magnetic or magnetizable pigment particles described herein.

[0031]

[0030] As used herein, the term "wet" refers to an uncured coating layer, for example, a coating layer in which non-spherical magnetic or magnetizable pigment particles can still change their position and orientation under the influence of external forces acting on them.

[0032]

[0031] The term "security document" refers to a document that is typically protected against counterfeiting or fraud by at least one security feature. Examples of security documents include, but are not limited to, documents of value and articles of value.

[0033]

[0032] The term "security feature" is used to describe an image, pattern, or graphic element that can be used for authentication purposes.

[0034]

[0033] When this detailed description refers to "preferred" embodiments / features, combinations of these "preferred" embodiments / features shall also be deemed to be disclosed to the extent that such combinations of "preferred" embodiments / features make technical sense.

[0035]

[0034] The present invention provides a method for making an optical effect layer (OEL) exhibiting one or more indicia (x30) on a substrate (x20), said OEL further exhibiting one or more indicia (x30) based on magnetically oriented non-spherical magnetic or magnetizable pigment particles. A preferred example of said process is shown in Figures 2A to 2K.

[0036] The method described herein comprises step a) of applying to the surface of a substrate (x20) described herein a mixture comprising non-spherical magnetic or magnetizable pigment particles described herein, one or more cationically curable compounds described herein, one or more radiation-curable coating compositions described herein, and a photoreactive compound not absorbing in the range of about 350 nm to about 470 nm described herein to form a coating layer (x10) described herein, the composition being in a first liquid state that allows for its application as a layer and is not yet cured (i.e., wet), allowing the pigment particles to move and rotate within the layer. Because the radiation-curable coating composition described herein is to be applied to the surface of the substrate (x20), the radiation-curable coating composition comprises at least a binder material and magnetic or magnetizable pigment particles, and the composition is in a form that allows for its processing in the desired printing or coating equipment. Preferably, step a) is carried out by a printing process preferably selected from the group consisting of screen printing, gravure printing, flexography, intaglio printing (also referred to in the art as engraved copper printing, engraved steel die printing), pad printing, and curtain coating, more preferably selected from the group consisting of intaglio printing, screen printing, gravure printing, pad printing, and flexography, even more preferably selected from the group consisting of screen printing, gravure printing, pad printing, and flexography. According to a preferred embodiment, step a) is carried out by a printing process selected from the group consisting of screen printing, gravure printing, and flexography.

[0037]

[0036] The non-spherical magnetic or magnetizable pigment particles described herein are preferably prolate or oblate ellipsoidal, platelet-shaped or needle-shaped magnetic or magnetizable pigment particles, or a mixture of two or more thereof, more preferably platelet-shaped particles.

[0038]

[0037] The non-spherical magnetic or magnetizable pigment particles described herein are defined as having, due to their non-spherical shape, anisotropic reflectivity for incident electromagnetic radiation for which the cured binder material is at least partially transparent. As used herein, the term "anisotropic reflectivity" indicates that the proportion of incident radiation reflected by a particle from a first angle to a certain (viewing) direction (a second angle) is a function of the particle's orientation, i.e., a change in particle orientation relative to the first angle can cause a different magnitude of reflection in the viewing direction. Preferably, the non-spherical magnetic or magnetizable pigment particles described herein have anisotropic reflectivity for incident electromagnetic radiation in part or the complete wavelength range from about 200 to about 2500 nm, more preferably from about 400 to about 700 nm, such that a change in particle orientation results in a change in reflection by the particle in a certain direction. As known by those skilled in the art, the magnetic or magnetizable pigment particles described herein differ from conventional pigments in that conventional pigment particles exhibit the same color and reflectance regardless of particle orientation, while the magnetic or magnetizable pigment particles described herein exhibit reflectance or color, or both, that are dependent on particle orientation.

[0039]

[0038] The radiation-curable coating composition described herein and the coating layer (x10) described herein contain the non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles described herein in an amount of preferably from about 5% to about 40% by weight, more preferably from 10% to about 30% by weight, the weight percentages being based on the total weight of the radiation-curable coating composition or coating layer (x10).

[0040] In the OELs described herein, the magnetic or magnetizable pigment particles described herein are dispersed in a radiation-curable coating composition containing a cured binder material that fixes the orientation and position of the magnetic or magnetizable pigment particles. The binder material, at least in its cured or solid state (also referred to herein as its second state), is at least partially transparent to electromagnetic radiation in the wavelength range of 200 nm to 2500 nm, i.e., a wavelength range typically referred to as the "optical spectrum" and including the infrared, visible, and UV portions of the electromagnetic spectrum. Thus, the particles contained in the binder material in its cured or solid state and their orientation-dependent reflectance can be seen through the binder material at some wavelengths within this range. Preferably, the cured binder material is at least partially transparent to electromagnetic radiation in the wavelength range of 200 nm to 800 nm, more preferably 400 nm to 700 nm. In this specification, the term "transmittance" indicates that the transmission of electromagnetic radiation through a 20 μm layer of cured binder material present in the OEL (excluding non-spherical magnetic or magnetizable pigment particles, but including all other optional components of the OEL, if such components are present) is at least 50%, more preferably at least 60%, and even more preferably at least 70% at the relevant wavelength. This can be determined by well-established test methods, for example, by measuring the transmittance of a test strip of the cured binder material (excluding non-spherical magnetic or magnetizable pigment particles) according to DIN 5036-3 (1979-11). If the OEL serves as a covert security feature, then technical means are typically required to detect the (completed) optical effect produced by the OEL under respective lighting conditions including selected non-visible wavelengths, which detection requires that the wavelength of the incident radiation be chosen outside the visible range, for example in the near-UV range.

[0041] Suitable examples of non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles described herein include, but are not limited to, pigment particles comprising a magnetic metal selected from the group consisting of cobalt (Co), iron (Fe), and nickel (Ni); a magnetic alloy of iron, manganese, cobalt, nickel, or a mixture of two or more thereof; a magnetic oxide of chromium, manganese, cobalt, iron, nickel, or a mixture of two or more thereof; or a mixture of two or more thereof. The term "magnetic," with respect to metals, alloys, and oxides, covers ferromagnetic or ferrimagnetic metals, alloys, and oxides. The magnetic oxides of chromium, manganese, cobalt, iron, nickel, or a mixture of two or more thereof may be pure or mixed oxides. Examples of magnetic oxides include, but are not limited to, hematite (Fe2O3), magnetite (Fe3O4), chromium dioxide (CrO2), magnetic ferrite (MFe2O4), magnetic spinel (MR2O4), magnetic hexaferrite (MFe 12 O 19 ), magnetic orthoferrite (RFeO3), and magnetic garnet M3R2(AO4)3, where M represents a divalent metal, R represents a trivalent metal, and A represents a tetravalent metal.

[0042]

[0041] Examples of non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles described herein include, but are not limited to, pigment particles comprising a magnetic layer M consisting of one or more of a magnetic metal such as cobalt (Co), iron (Fe), or nickel (Ni); and a magnetic alloy of iron, cobalt, or nickel, and the magnetic or magnetizable pigment particles may be a multilayer structure comprising one or more further layers. Preferably, the one or more further layers are layer A independently of one or more selected from the group consisting of metal fluorides such as magnesium fluoride (MgF), silicon oxide (SiO), silicon dioxide (SiO), titanium oxide (TiO), and aluminum oxide (AlO), more preferably silicon dioxide (SiO); or layer B independently of one or more selected from the group consisting of metals and metal alloys, preferably selected from the group consisting of reflective metals and reflective alloys, more preferably one or more selected from the group consisting of silver (Ag), aluminum (Al), chromium (Cr), and nickel (Ni), even more preferably aluminum (Al); or a combination of one or more layers A such as those described above and one or more layers B such as those described above. Representative examples of platelet-shaped magnetic or magnetizable pigment particles having such a multilayer structure include, but are not limited to, A / M multilayer structures, A / M / A multilayer structures, A / M / B multilayer structures, A / B / M / A multilayer structures, A / B / M / B multilayer structures, A / B / M / B / A / multilayer structures, B / M multilayer structures, B / M / B multilayer structures, B / A / M / A multilayer structures, B / A / M / B multilayer structures, and B / A / M / B / A / multilayer structures, where Layer A, Magnetic Layer M, and Layer B are selected from those described above.

[0043]

[0042] The radiation-curable coating compositions described herein may comprise non-spherical, preferably platelet-shaped, optically variable magnetic or magnetizable pigment particles, and / or non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles without optically variable properties. Preferably, at least a portion of the magnetic or magnetizable pigment particles described herein are constituted by non-spherical, preferably platelet-shaped, optically variable magnetic or magnetizable pigment particles. In addition to the overt security provided by the color-shifting properties of the optically variable magnetic or magnetizable pigment particles, which allow articles or security documents bearing an ink, coating composition, or coating layer comprising the optically variable magnetic or magnetizable pigment particles described herein to be easily detected, recognized, and / or distinguished from their potential counterfeits using unaided human senses, the optical properties of the optically variable magnetic or magnetizable pigment particles may also be used as a machine-readable tool for recognition of the OEL. Thus, the optical properties of the optically variable magnetic or magnetisable pigment particles may simultaneously be used as a covert or semi-covert security feature in an authentication process in which the optical (e.g. spectral) properties of the pigment particles are analysed, thus improving counterfeit resistance.

[0044]

[0043] The use of non-spherical, preferably platelet-shaped, optically variable magnetic or magnetizable pigment particles in the coating layer to produce the OEL enhances the significance of the OEL as a security feature in security document applications, since such materials are reserved for the security document printing industry and are not generally commercially available.

[0045] As mentioned above, preferably at least a portion of the non-spherical, preferably platelet-shaped, magnetic or magnetisable pigment particles are constituted by non-spherical, preferably platelet-shaped, optically variable magnetic or magnetisable pigment particles, which are preferably selected from the group consisting of magnetic thin film interference pigment particles, magnetic cholesteric liquid crystal pigment particles, interference coated pigment particles comprising a magnetic material and mixtures of two or more thereof.

[0046]

[0045] Magnetic thin film interference pigment particles are known to those skilled in the art and are disclosed, for example, in U.S. Pat. No. 4,838,648; WO 2002 / 073250; EP 0 686675; WO 2003 / 000801; U.S. Pat. No. 6,838,166; WO 2007 / 131833; EP 2 402 401; WO 2019 / 103937; WO 2020 / 006286, and the documents cited therein. Preferably, the magnetic thin film interference pigment particles include pigment particles having a five-layer Fabry-Perot multilayer structure, and / or pigment particles having a six-layer Fabry-Perot multilayer structure, and / or pigment particles having a seven-layer Fabry-Perot multilayer structure, and / or pigment particles having a multilayer structure combining one or more multilayer Fabry-Perot structures.

[0047]

[0046] A preferred five-layer Fabry-Perot multilayer structure consists of a multilayer structure of absorber / dielectric / reflector / dielectric / absorber, where the reflector and / or absorber are also magnetic layers, and preferably the reflector and / or absorber are magnetic layers containing nickel, iron, and / or cobalt, and / or magnetic alloys containing nickel, iron, and / or cobalt, and / or magnetic oxides containing nickel (Ni), iron (Fe), and / or cobalt (Co).

[0048] A preferred six-layer Fabry-Perot multilayer structure consists of an absorber / dielectric / reflector / magnetic / dielectric / absorber multilayer structure.

[0049] A preferred seven-layer Fabry-Perot multilayer structure consists of an absorber / dielectric / reflector / magnetic / reflector / dielectric / absorber multilayer structure such as that disclosed in US Pat. No. 4,838,648.

[0050]

[0049] Preferred pigment particles having a multilayer structure combining one or more Fabry-Perot structures are described in WO 2019 / 103937, which consist of a combination of at least two Fabry-Perot structures, each independently comprising a reflector layer, a dielectric layer, and an absorber layer, and the reflector and / or absorber layers can each independently comprise one or more magnetic materials, and / or a magnetic layer is sandwiched between the two structures. WO 2020 / 006 / 286 and EP 3587500 disclose further preferred pigment particles having a multilayer structure.

[0051]

[0050] Preferably, the reflector layer described herein is selected from the group consisting of metals and metal alloys, preferably selected from the group consisting of reflective metals and reflective metal alloys, more preferably selected from the group consisting of aluminum (Al), silver (Ag), copper (Cu), gold (Au), platinum (Pt), tin (Sn), titanium (Ti), palladium (Pd), rhodium (Rh), niobium (Nb), chromium (Cr), nickel (Ni), and alloys thereof, even more preferably independently from one or more selected from the group consisting of aluminum (Al), chromium (Cr), nickel (Ni), and alloys thereof, even more preferably independently from aluminum (Al). Preferably, the dielectric layer is independently one or more independently selected from the group consisting of metal fluorides such as magnesium fluoride (MgF), aluminum fluoride (AlF), cerium fluoride (CeF), lanthanum fluoride (LaF), sodium aluminum fluoride (e.g., NaAlF), neodymium fluoride (NdF), samarium fluoride (SmF), barium fluoride (BaF), calcium fluoride (CaF), lithium fluoride (LiF), and metal oxides such as silicon oxide (SiO), silicon dioxide (SiO), titanium oxide (TiO), aluminum oxide (AlO), more preferably magnesium fluoride (MgF) and silicon dioxide (SiO), and even more preferably magnesium fluoride (MgF). Preferably, the absorber layer is independently one or more selected from the group consisting of aluminum (Al), silver (Ag), copper (Cu), palladium (Pd), platinum (Pt), titanium (Ti), vanadium (V), iron (Fe), tin (Sn), tungsten (W), molybdenum (Mo), rhodium (Rh), niobium (Nb), chromium (Cr), nickel (Ni), metal oxides thereof, metal sulfides thereof, metal carbides thereof, and metal alloys thereof, more preferably selected from the group consisting of chromium (Cr), nickel (Ni), metal oxides thereof, and metal alloys thereof, even more preferably selected from the group consisting of chromium (Cr), nickel (Ni), and alloys thereof.Preferably, the magnetic layer comprises nickel (Ni), iron (Fe), and / or cobalt (Co); and / or a magnetic alloy comprising nickel (Ni), iron (Fe), and / or cobalt (Co); and / or a magnetic oxide comprising nickel (Ni), iron (Fe), and / or cobalt (Co). When magnetic thin film interference pigment particles comprising a seven-layer Fabry-Perot structure are preferred, it is particularly preferred that the magnetic thin film interference pigment particles comprise a seven-layer Fabry-Perot absorber / dielectric / reflector / magnetic / reflector / dielectric / absorber multilayer structure consisting of a Cr / MgF2 / Al / Ni / Al / MgF2 / Cr multilayer structure.

[0052] The magnetic thin film interference pigment particles described herein are considered to be safe for human health and the environment, and may be, for example, multilayer pigment particles based on a five-layer Fabry-Perot multilayer structure, a six-layer Fabry-Perot multilayer structure, a seven-layer Fabry-Perot multilayer structure, or pigment particles having a multilayer structure combining one or more Fabry-Perot multilayer structures, said pigment particles comprising one or more magnetic layers comprising a magnetic alloy having a substantially nickel-free composition comprising about 40% to about 90% by weight iron, about 10% to about 50% by weight chromium, and about 0% to about 30% by weight aluminum. Representative examples of multilayer pigment particles considered to be safe for human health and the environment can be found in EP 2402401, the entire contents of which are incorporated herein by reference.

[0053] Suitable magnetic cholesteric liquid crystal pigment particles exhibiting optically variable properties include, but are not limited to, magnetic single-layer cholesteric liquid crystal pigment particles and magnetic multi-layer cholesteric liquid crystal pigment particles. Such pigment particles are disclosed, for example, in WO 2006 / 063926, U.S. Pat. No. 6,582,781, and U.S. Pat. No. 6,531,221. WO 2006 / 063926 discloses a monolayer and pigment particles obtained therefrom, which have high brightness and color shifting properties and further specific properties such as magnetization. The disclosed monolayer and pigment particles are obtained therefrom by grinding the monolayer and include a three-dimensionally crosslinked cholesteric liquid crystal mixture and magnetic nanoparticles. U.S. Pat. No. 6,582,781 and U.S. Pat. No. 6,410,130 disclose a method for producing a cholesteric liquid crystal pigment having a sequence A. 1 / B / A 2 The present invention discloses platelet-shaped cholesteric multilayer pigment particles comprising: 1 and A 2 A and B may be the same or different and each comprise at least one cholesteric layer, and B is an intermediate layer that absorbs all or part of the light transmitted by layers A1 and A2 and confers magnetic properties to said intermediate layer. U.S. Patent No. 6,531,221 discloses platelet-shaped cholesteric multilayer pigment particles comprising the sequence A / B and optionally C, where A and C are absorbing layers containing pigment particles that confers magnetic properties, and B is a cholesteric layer.

[0054]

[0053] Suitable interference-coated pigment particles containing one or more magnetic materials include, but are not limited to, structures consisting of a substrate selected from the group consisting of a core coated with one or more layers, wherein at least one or more layers of the core have magnetic properties. For example, suitable interference-coated pigment particles include a core made of a magnetic material such as those described above, coated with one or more layers made of one or more metal oxides, or they have a structure consisting of a core made of synthetic or natural mica, layered silicates (e.g., talc, kaolin, and sericite), glass (e.g., borosilicate), silicon dioxide (SiO2), aluminum oxide (Al2O3), titanium oxide (TiO2), graphite, and mixtures of two or more thereof. Additionally, one or more additional layers, such as color layers, may be present.

[0055]

[0054] The non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles described herein preferably have a size d50 (measured by direct optical particle size distribution) of from about 2 μm to about 50 μm.

[0056]

[0055] The non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles described herein may be surface treated to protect them from possible deterioration of the coating compositions and coating layers and / or to promote their incorporation into said coating compositions and coating layers, typically using corrosion-inhibiting materials and / or wetting agents.

[0057] As described herein, the method described herein includes steps c) and e) of at least partially curing the coating layer (x10) to a second state to fix the magnetic or magnetizable pigment particles in their adopted position and orientation. In the first liquid state of the radiation-curable coating composition, the magnetic or magnetizable pigment particles can move and rotate, and in the second state, the magnetic or magnetizable pigment particles are fixed and set by using some type of radiation-curable coating composition. For example, components of the radiation-curable coating composition other than the non-spherical magnetic or magnetizable pigment particles may be in the form of an ink or radiation-curable coating composition, such as those used in security applications, e.g., printing banknotes. The aforementioned first and second states are brought about by using a material that exhibits an increase in viscosity in response to exposure to electromagnetic radiation. That is, when the flowable binder material is cured or solidified, said binder material changes to a second state and the non-spherical magnetic or magnetizable pigment particles are fixed in their current position and orientation and can no longer move or rotate within the binder material. As used herein, by "at least partially curing the coating layer (x10)" it is meant that the non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles are fixed / suspended in their adopted position and orientation and can no longer move or rotate (also referred to in the art as "pinning" the particles).

[0058] The radiation-curable coating composition used to prepare the coating layer (x10) described herein comprises non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles as described herein, and one or more compounds that do not absorb in the range of about 350 nm to about 470 nm as described herein. Radiation curing, particularly UV-Vis curing, advantageously leads to a momentary increase in the viscosity of the coating composition after exposure to radiation, thus preventing further migration of the pigment particles and, consequently, loss of information after the magnetic orientation step.

[0059]

[0058] A radiation-curable coating composition comprising a mixture of non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles as described herein and a photoreactive compound that does not absorb in the range of about 350 nm to about 470 nm as described herein comprises both a cationically curable compound and a radiation-curable compound. In other words, the radiation-curable coating composition, preferably a UV-Vis curable coating composition as described herein, is a hybrid curable coating composition.

[0060]

[0059] The radiation curable coating compositions containing the non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles described herein preferably contain the cationically curable compound in an amount of about 45% to 75% by weight and the radiation curable coating composition in an amount of about 2% to 30% by weight, more preferably about 2% to 25% by weight, the weight percentages being based on the total weight of the radiation curable coating composition.

[0061]

[0060] Cationically curable compositions are cured by a cationic mechanism that typically involves the activation by radiation of one or more compounds that react and / or crosslink monomers and / or oligomers, thereby solidifying the coating composition, liberating a cationic species, such as an acid, which then initiates curing. Preferably, the one or more cationically curable compounds are selected from the group consisting of vinyl ethers, propenyl ethers, epoxides, oxetanes, glycidyl ethers, and tetrahydrofuran, cyclic ethers, lactones, cyclic thioethers, vinyl thioethers, propenyl thioethers, hydroxyl-containing compounds, and mixtures thereof, preferably cyclic ethers, such as vinyl ethers, propenyl ethers, epoxides, oxetanes, and tetrahydrofuran, lactones, and mixtures thereof, more preferably cyclic ethers, such as vinyl ethers, epoxides, oxetanes, and tetrahydrofuran, and mixtures thereof.

[0062]

[0061] Preferably, the radiation-curable coating composition comprising the non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles described herein comprises one or more cycloaliphatic epoxides, which may be difunctional or polyfunctional, and may optionally further comprise one or more components selected from the group consisting of vinyl ethers, oxetanes, and mixtures thereof.

[0063] Preferably, one or more cycloaliphatic epoxides independently described herein contain at least one cyclohexane group and at least two epoxy groups. Preferred cycloaliphatic epoxides contain more than one (i.e., at least two) cyclohexane groups and have structural formula (I): [ka] In the formula, -X- represents a single bond or a divalent group containing one or more atoms. According to one embodiment, X is a divalent hydrocarbon group that is a linear or branched alkylene group having 1 to 18 carbon atoms, including, but not limited to, methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene. According to one embodiment, X is a divalent alicyclic hydrocarbon group or a cycloalkyne group, such as 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylidene. According to one embodiment, X is a divalent group containing one or more oxygen-containing linking groups, which are -CO-, -O-CO-O-, -COO-, and -O-. According to one embodiment, preferred epoxy derivatives contain more than one cyclohexene oxide group and have structural formula (I), where X is a divalent group containing one or more oxygen-containing linking groups that are -CO-, -O-CO-O-, -COO-, -O-, and have structural formula (II), (III), or (IV): [ka] corresponds to 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, where R1 to R9 are independently hydrogen or a linear or branched alkyl radical containing 1 to 12 carbon atoms, preferably 1 to 3 carbon atoms (e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, hexyl, octyl, decyl, and dodecyl), and preferably, the cycloaliphatic epoxides having structural formula (II) are 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methyl-cyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate, 3,4-epoxy-2-methyl-cyclohexylmethyl-3,4-epoxy-2-methyl-cyclohexanecarboxylate, and 3,4-epoxy-4-methyl-cyclohexylmethyl-3,4-epoxy-4-methylcyclohexanecarboxylate; [ka] corresponds to a cycloaliphatic diepoxide ester of a dicarboxylic acid, R1-R9 are independently hydrogen or a straight-chain or branched alkyl radical containing 1 to 12 carbon atoms, preferably 1 to 3 carbon atoms (e.g., methyl, ethyl, n-propyl, isopropyl, butyl, hexyl, octyl, and decyl), A is a valence bond or a straight-chain or branched divalent hydrocarbon radical, generally containing 1 to 12 carbon atoms, preferably 3 to 8 carbon atoms, such as an alkylene radical (e.g., trimethylene, tetramethylene, hexamethylene, and 2-ethylhexyl). cyclohexane) and alicyclic radicals (e.g., 1,4-cyclohexane, 1,3-cyclohexane, and 1,2-cyclohexane), preferably, the alicyclic diepoxide esters of dicarboxylic acids having structural formula (III) are bis(3,4-epoxycyclohexylmethyl)adipate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, bis(3,4-epoxycyclohexylmethyl)oxalate, bis(3,4-epoxycyclohexylmethyl)pimelate, and bis(3,4-epoxycyclohexylmethyl)sebacate; [ka] R1 to R9 are independently hydrogen or a linear or branched hydrocarbon group containing 1 to 3 carbon atoms, and a preferred example of an alicyclic diepoxide having structural formula (IV) is 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-meta-dioxane.

[0064]

[0063] For embodiments in which the radiation-curable coating composition includes one or more cycloaliphatic epoxides described, the one or more cycloaliphatic epoxides described are preferably present in an amount of about 15% to 75% by weight, the weight percentage being based on the total weight of the radiation-curable coating composition.

[0065] For embodiments in which the radiation-curable coating composition includes one or more vinyl ethers described herein, the one or more vinyl ethers are preferably present in an amount of about 0.1% to 55% by weight, the weight percentage being based on the total weight of the radiation-curable coating composition. Vinyl ethers are known in the art to accelerate cure and reduce tack, thereby limiting the risk of blocking and offset when printed substrates are stacked immediately after printing and curing. They also improve the physical and chemical resistance of optical effect layers (OELs) and improve the flexibility of the printed, cured layers, which can be advantageous when the radiation-curable coating composition is printed on plastic or polymeric substrates. Vinyl ethers also help reduce the viscosity of the composition while strongly copolymerizing with the ink vehicle.

[0066]

[0065] Examples of preferred vinyl ethers include methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, ethylhexyl vinyl ether, octadecyl vinyl ether, dodecyl vinyl ether, isopropyl vinyl ether, tert-butyl vinyl ether, tert-amyl vinyl ether, cyclohexyl vinyl ether, cyclohexanedimethanol monovinyl ether, cyclohexanedimethanol divinyl ether, 4-(vinyloxymethyl)cyclohexylmethylbenzoate, phenyl vinyl ether, methylphenyl vinyl ether, methoxyphenyl vinyl ether, 2-chloroethyl vinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 1,6-hexanediol monovinyl ether, ethylene glycol divinyl ether, ethylene glycol monovinyl ether, 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, ether, 4-(vinyloxy)butyl benzoate, bis[4-(vinyloxy)butyl]adipate, bis[4-(vinyloxy)butyl]succinate, bis[4-(vinyloxymethyl)cyclohexylmethyl]glutarate, 4-(vinyloxy)butyl stearate, trimethylolpropane trivinyl ether, propenyl ether of propylene carbonate, diethylene glycol monovinyl ether, diethylene glycol divinyl ether, ethylene glycol butyl vinyl ether, dipropylene glycol divinyl ether, triethylene glycol divinyl ether, triethylene glycol methyl vinyl ether, triethylene glycol monobutyl vinyl ether, tetraethylene glycol divinyl ether, poly(tetrahydrofuran) divinyl ether, polyethylene glycol-520 methyl vinyl ether, pluriol-E200 divinyl ether, tris[4-(vinyloxy)butyl]trimellitate, 1,4-bis(2-vinyloxyethoxy)benzene, 2,Examples of suitable vinyl ethers include 2-bis(4-vinyloxyethoxyphenyl)propane, bis[4-(vinyloxy)methyl]cyclohexyl]methyl]terephthalate, and bis[4-(vinyloxy)methyl]cyclohexyl]methyl]isophthalate. Suitable vinyl ethers are commercially available from BASF under the names EVE, IBVE, DDVE, ODVE, BDDVE, DVE-2, DVE-3, CHVE, CHDM-di, and HBVE. One or more of the vinyl ethers described herein may be hydroxy-modified or (meth)acrylate-modified (e.g., VEEAR®, Nippon Shokubai's 2-(2-vinyloxyethoxy)ethyl acrylate (CAS: 86273-46-3)).

[0067] For embodiments in which the radiation-curable coating composition includes one or more oxetanes described herein, the one or more oxetanes are preferably present in an amount of about 0.1% to 20% by weight, the weight percentage being based on the total weight of the radiation-curable coating composition. Oxetanes are known in the art to accelerate cure and reduce tack, thereby limiting the risk of blocking and offset when print sheets are placed on top of each other immediately after print curing. They also help reduce ink viscosity while strongly copolymerizing with the composition.

[0068]

[0067] Preferred examples of oxetanes include trimethylene oxide, 3,3-dimethyloxetane, trimethylolpropaneoxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane, 3,3-dicyclomethyloxetane, 3-ethyl-3-phenoxymethyloxetane, bis([1-ethyl(3-oxetanyl)]methyl)ether, 1,4-bis[3-ethyl-3-oxetanylmethoxy)methyl]benzene, 3,3-dimethyl-2(p-methoxy-phenyl)-oxetane, 3-ethyl-[(tri-ethoxysilylpropoxy)methyl]oxetane, 4,4-bis(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, and 3,3-dimethyl-2(p-methoxy-phenyl)oxetane. The oxetane(s) described herein may be hydroxy-modified or (meth)acrylate-modified (for example: Lambson's Uvi-Cure S170 CAS (CAS: 37674-57-0)).

[0069] The radiation-curable coating compositions described herein may further comprise one or more polyhydroxy compounds. For embodiments in which the radiation-curable coating composition comprises one or more polyhydroxy compounds described herein, the one or more polyhydroxy compounds are preferably present in an amount of about 15% by weight or less, more preferably about 1% to about 10% by weight, the weight percentages being based on the total weight of the radiation-curable coating composition. Polyhydroxy compounds are known to improve adhesion to substrates known to exhibit poor adhesion, such as plastic or polymer substrates that are increasingly prevalent in the field of security documents, particularly banknotes.

[0070] The one or more polyhydroxy compounds described herein preferably contain more than two hydroxyl groups and may be linear, branched, or hyperbranched (also referred to in the art as arborescent). Preferably, the one or more polyhydroxy compounds described herein are multifunctional compounds, such as trifunctional, tetrafunctional, hexafunctional compounds, etc.

[0071]

[0070] The one or more polyhydroxy compounds described herein are preferably selected from the group consisting of polyhydroxy derivatives of aliphatic or aromatic polyethers, polyhydroxy derivatives of polyesters, polyhydroxy derivatives of polycarbonates, glycerol, trimethylolpropane, di-trimethylolpropane, pentaerythritol, dipentaerythritol, and mixtures thereof.

[0072]

[0071] One or more polyhydroxy compounds described herein may be at least partially alkoxylated. Thus, one or more polyhydroxy compounds described herein may have alkoxylated units, preferably ethoxylated and / or propoxylated units. According to a preferred embodiment, one or more polyhydroxy compounds described herein are selected from the group consisting of trifunctional compounds, preferably glycerol and trimethylolpropane, tetrafunctional compounds, preferably di-trimethylolpropane and pentaerythritol, hexafunctional compounds, preferably dipentaerythritol, and mixtures thereof, and said compounds, preferably said trimethylolpropane, pentaerythritol, and dipentaerythritol, may be alkoxylated (ethoxylated and / or propoxylated).

[0073] The radiation-curable coating compositions described herein may further comprise one or more glycidyl ether compounds. For embodiments in which the radiation-curable coating composition comprises one or more glycidyl ether compounds described herein, the one or more glycidyl ethers are preferably present in an amount of about 1% to about 5% by weight, the weight percentage being based on the total weight of the radiation-curable coating composition, or 1% to 25% by weight based on the total weight of the top coating composition. The use of epoxides in UV-Vis radiation-curable inks helps to accelerate cure and reduce tackiness, as well as reduce the viscosity of the ink while strongly copolymerizing with the ink vehicle. Preferred examples of epoxides other than the cycloaliphatic epoxides described herein include, but are not limited to, cyclohexanedimethanol diglycidyl ether, poly(ethylene glycol) diglycidyl ether, poly(propylene glycol) diglycidyl ether, butanediol diglycidyl ether, hexanediol diglycidyl ether, bisphenol-A diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, pentaerythritol tetraglycidyl ether, butyl glycidyl ether, p-tert-butylphenyl glycidyl ether, hexadecyl glycidyl ether, 2-ethyl-hexyl glycidyl ether, octyl glycidyl ether, decyl glycidyl ether, dodecyl glycidyl ether, tetradecyl glycidyl ether, C12 / C14 alkyl glycidyl ethers, C13 / C15 alkyl glycidyl ethers, and mixtures thereof. Suitable epoxides other than cycloaliphatic epoxides are commercially available from EMS Griltech under the registered trademark Grilonit® (eg Grilonit® V51-63 or RV1806).

[0074]

[0073] The radiation curable compound is cured by a free radical mechanism consisting of the energy activation of one or more photoinitiators, which liberate free radicals that subsequently initiate polymerization to form the binder. Preferably, the radiation curable compound is preferably selected from the group consisting of (meth)acrylates, preferably selected from the group consisting of epoxy (meth)acrylates, (meth)acrylated oils, polyester and polyether (meth)acrylates, aliphatic or aromatic urethane (meth)acrylates, silicone (meth)acrylates, acrylic (meth)acrylates, and mixtures thereof.

[0075] According to one embodiment, the radiation-curable coating composition comprises one or more radiation-curable oligomers described herein, preferably in an amount of about 2% to 30% by weight, more preferably about 5% to 30% by weight, and even more preferably about 5% to 25% by weight, the weight percentages being based on the total weight of the radiation-curable coating composition. The radiation-curable oligomers described herein refer to relatively high molecular weight oligomeric compounds having a weight-average molecular weight (MW) of ≥ 500 g / mol. The radiation-curable oligomers described herein are preferably (meth)acrylate oligomers, which may be branched or essentially linear, and the (meth)acrylate functional group(s) can be terminal groups and / or pendant side groups attached to the oligomer backbone, respectively. In the context of the present invention, the term "(meth)acrylate" refers to acrylates and the corresponding methacrylates. Preferably, the radiation-curable oligomer is selected from the group consisting of (meth)acrylic acid oligomers, urethane (meth)acrylate oligomers, polyester (meth)acrylate oligomers, polyether-based (meth)acrylate oligomers, epoxy (meth)acrylate oligomers, and mixtures thereof, more preferably epoxy (meth)acrylate oligomers and mixtures thereof.

[0076]

[0075] Suitable examples of epoxy (meth)acrylate oligomers include, but are not limited to, aliphatic epoxy (meth)acrylate oligomers, particularly mono(meth)acrylates, di(meth)acrylates, and tri(meth)acrylates, and aromatic epoxy (meth)acrylate oligomers. Suitable examples of (meth)acrylate monomers include tri(meth)acrylates, tetra(meth)acrylates, and mixtures thereof. The one or more tri(meth)acrylates described herein may be trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, alkoxylated (particularly ethoxylated or propoxylated) trimethylolpropane triacrylate, alkoxylated (particularly ethoxylated or propoxylated) trimethylolpropane trimethacrylate, alkoxylated (particularly ethoxylated or propoxylated) glycerin triacrylate, pentaerythritol triacrylate, The one or more tetra(meth)acrylates described herein are selected from the group consisting of ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkoxylated (especially ethoxylated or propoxylated) pentaerythritol triacrylate, and mixtures thereof, preferably selected from the group consisting of trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) trimethylolpropane triacrylate, alkoxylated (especially ethoxylated or propoxylated) glycerin triacrylate, pentaerythritol triacrylate, and mixtures thereof, preferably selected from the group consisting of ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, alkoxylated (e.g., ethoxylated and propoxylated) pentaerythritol tetra(meth)acrylate, and mixtures thereof, preferably selected from the group consisting of ditrimethylolpropane tetra(meth)acrylate, alkoxylated pentaerythritol tetra(meth)acrylate, and mixtures thereof.

[0077] The radiation-curable coating compositions described herein may further comprise from about 0.1 to about 15 wt %, preferably from about 0.1 to about 10 wt %, of one or more reactive diluents preferably selected from mono(meth)acrylates, di(meth)acrylates, and mixtures thereof, the weight percentages being based on the total weight of the radiation-curable coating composition. Suitable mono(meth)acrylates may be selected from alkyl(meth)acrylates, cycloalkyl(meth)acrylates, benzyl(meth)acrylate, phenyl(meth)acrylate (including phenoxyalkyl(meth)acrylates, such as phenoxyethyl acrylate), cyclic trimethylolpropane formal acrylate, tetrahydrofurfuryl acrylate, aliphatic urethane(meth)acrylates, and alkoxylated (particularly ethoxylated or propoxylated) compounds thereof.Suitable di(meth)acrylates include, but are not limited to, ethylene glycol diacrylate; ethylene glycol dimethacrylate; 1,4-butanediol diacrylate; 1,4-butanediol dimethacrylate; 1,3-butanediol diacrylate; 1,3-butanediol dimethacrylate; 2-methyl-1,3-propanediol diacrylate; 3-methyl-1,5-pentanediol diacrylate; 2-butyl-2-ethyl-1,3-propanediol diacrylate; 1,6-hexanediol diacrylate; 1,6-hexanediol dimethacrylate; neopentyl glycol diacrylate; neopentyl glycol dimethacrylate; 1,9-nonanediol diacrylate; 1,9-nonanediol dimethacrylate; 1,10-decanediol diacrylate; 1,10-decanediol dimethacrylate; alkoxylated (especially ethoxylated and propoxylated) 1,6-hexanediol diacrylate. Diol diacrylate; propoxylated neopentyl glycol diacrylate; ethoxylated 2-methyl-1,3-propanediol diacrylate; tricyclodecane dimethanol diacrylate; diethylene glycol diacrylate; diethylene glycol dimethacrylate; dipropylene glycol diacrylate; triethylene glycol diacrylate; triethylene glycol dimethacrylate; tripropylene glycol diacrylate; tripropylene glycol dimethacrylate; tetraethylene glycol diacrylate; tetraethylene glycol dimethacrylate; polyethylene glycol 200 / 400 / 600 diacrylate; polyethylene glycol 200 / 400 / 600 dimethacrylate; ethoxylated (EO2 / EO3 / EO4 / EO10) bisphenol A diacrylate; and ethoxylated (EO2 / EO3 / EO4 / EO10) bisphenol A dimethacrylate.

[0078]

[0077] Radiation-curable coating compositions containing the non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles described herein may further comprise one or more coloring components selected from the group consisting of organic pigment particles, inorganic pigment microparticles, and organic dyes, and / or one or more additives. Examples of the latter include, but are not limited to, compounds and materials used to adjust the physical, rheological, and chemical parameters of the coating composition, such as viscosity (e.g., solvents, thickeners, and surfactants), consistency (e.g., anti-settling agents, fillers, and plasticizers), foamability (e.g., antifoaming agents), lubricity (waxes, oils), UV stability (light stabilizers), adhesion, antistatic properties, and storage stability (polymerization inhibitors). The additives described herein may be present in the coating composition in amounts and forms known in the art, including so-called nanomaterials, in which at least one dimension of the additive is in the range of 1 to 1000 nm.

[0079]

[0078] The radiation curable coating compositions comprising the non-spherical, preferably platelet-shaped, magnetic or magnetizable pigment particles described herein may further comprise one or more marking substances or identification additives selected from the group consisting of magnetic materials (different from the magnetic or magnetizable pigment particles described herein), luminescent materials, electroluminescent materials, upconverting materials, electrically conductive materials, and infrared absorbing materials, and / or one or more machine-readable materials. As used herein, the term "machine-readable material" refers to a material that exhibits at least one unique property that is detectable by a device or machine and that can be included in the coating for such detection and / or authentication to provide a method for authenticating the coating or an article comprising said coating by use of a specific device.

[0080] The radiation-curable coating compositions described herein may be prepared by dispersing or mixing the magnetic or magnetizable pigment particles described herein and one or more additives, when present, in the presence of a binder material described herein to form a liquid composition. If present, the one or more photoinitiators may be added to the composition during the dispersing or mixing step of all the other ingredients, or may be added at a later stage, i.e., after formation of the liquid coating composition.

[0081] The method described herein further comprises, after step a) described herein, step b) of applying at least partially onto the coating layer (x10) described herein, a top coating composition described herein, wherein the top coating composition described herein is applied in the form of one or more indicia (x30) described herein and partially overlaps (i.e., overlaps in at least one area) the coating layer (x10) described herein, and wherein the radiation-curable coating composition of coating layer (x10) is in a wet, unpolymerized state and the magnetic or magnetizable pigment particles are free to move and rotate.

[0082]

[0081] As used herein, the term "indicia" refers to continuous and discontinuous layers of identifying markings or signs or patterns. Preferably, the one or more indicia (x30) described herein are selected from the group consisting of codes, symbols, alphanumeric symbols, motifs, geometric patterns (e.g., circles, triangles, and regular or irregular polygons), letters, words, numbers, logos, figures, portraits, and combinations thereof. Examples of codes include coded marks such as coded alphanumeric data, one-dimensional barcodes, two-dimensional barcodes, QR codes, data matrices, and IR-readable codes. The one or more indicia (x30) described herein may be solid indicia and / or raster indicia.

[0083] The top coating composition described herein is applied in the form of one or more indicia (x30) as described herein by an application process, preferably a non-contact fluid micro-dispensing process preferably selected from the group consisting of spray coating, aerosol inkjet printing, electrohydrodynamic printing, slot-die coating, and inkjet printing, more preferably an inkjet printing process, said non-contact fluid micro-dispensing printing process being a variable information printing method that allows for the unique creation of one or more indicia (x30) on or in the optical effect layer (OEL) as described herein. The application process is selected as a function of the design and resolution of the indicia or indicia to be created.

[0084] Inkjet printing can be advantageously used to create optical effect layers (OELs) exhibiting one or more indicia described herein, including variable halftones. Inkjet halftone printing is a reproduction technique that simulates continuous-tone images containing an infinite number of colors or shades of gray through the application of variable inkjet coverage or basis weight.

[0085] Spray coating is a technique in which a composition is forced through a nozzle to form a fine aerosol. A carrier gas and electrostatic charge may be involved to function to direct the aerosol onto the surface to be printed. Spray printing makes it possible to print spots and lines. Compositions suitable for spray printing typically have a viscosity of about 10 mPa.s to about 1 Pa.s at 25°C (1000 s -1 ) The resolution of spray coating printing is in the millimeter range. Spray printing is described, for example, in F.C. K. Rebs, Solar Energy Materials & Solar Cells (2009), 93, 407.

[0086] Aerosol inkjet printing (AJP) is a new non-contact direct-write approach aimed at producing fine features on a wide range of substrates. AJP is compatible with a wide range of materials and freeform deposition, enabling high resolution (on the order of about 10 micrometers) along with relatively large separation distances (e.g., 1-5 mm) in addition to orientation independence. The technique involves aerosol generation using ultrasonic or pneumatic atomizers, typically with a viscosity of about 1 mPa.s to about 1 Pa.s at 25°C (1000 s -1 Aerosols are generated from compositions having a viscosity of about 1000 psi. Aerosol jet printing is described, for example, in NJ Wilkinson et al., The International Journal of Advanced Manufacturing Technology (2019) 105:4599-4619.

[0087] Electrohydrodynamic inkjet printing is a high-resolution inkjet printing technique. Electrohydrodynamic inkjet printing uses an externally applied electric field to manipulate droplet size, ejection frequency, and placement on a substrate to achieve higher resolution than conventional inkjet printing while maintaining high production speeds. The resolution of electrohydrodynamic inkjet printing is about two orders of magnitude higher than conventional inkjet printing techniques, and therefore it can be used to direct nanoscale and microscale patterns. Electrohydrodynamic inkjet printing may be used in both DOD or continuous mode. Electrohydrodynamic inkjet printing compositions typically have a viscosity of about 1 mPa.s to about 1 Pa.s at 25°C (1000 s -1 ) The electrohydrodynamic inkjet printing technique is described, for example, in PV Raje and NC Murmu, International Journal of Emerging Technology and Advanced Engineering, (2014), 4(5), pp. 174-183.

[0088] Slot die coating is a one-dimensional coating technique. Slot die coating allows for the coating of stripes of material, which is well suited to creating multilayer coatings in which stripes of different materials are layered on top of each other. Alignment of the pattern is achieved by moving the coating head along a direction perpendicular to the direction of web movement. A slot die coating head includes a mask that defines slots in the coating head through which the slot die coating ink is dispersed. An example of a slot die coating head is described in F.C.K.rebs, Solar Energy Materials & Solar Cells (2009), 93, pp. 405-406. Compositions suitable for slot die coating typically have a viscosity of about 1 mPa.s to about 20 mPa.s at 25°C (1000 s -1 ) viscosity.

[0089] According to one embodiment, the top coating composition described herein is printed in the form of one or more indicia (x30) as described herein by an inkjet printing process, preferably a continuous inkjet (CI) printing process, or a drop-on-demand (DOD) inkjet printing process, more preferably a drop-on-demand (DOD) inkjet printing process. Drop-on-demand (DOD) printing is a non-contact printing process, where droplets are generally simply created by an ejection mechanism as needed for printing, rather than by destabilizing a jet. Depending on the mechanism used in the printhead to create the droplets, DOD printing can be performed using a variety of methods, including piezoelectric impulse, thermal jet, valve jet (from about 1 mPa.s to about 1 Pa.s at 25°C (1000 s -1 ) viscous), and electrostatic processes.

[0090]

[0089] The top coating compositions described herein comprise one or more curable compounds, said curable compounds being radiation-curable compounds, cationically-curable compounds, or mixtures thereof. According to a preferred embodiment, the top coating compositions described herein comprise a radiation-curable compound preferably selected from the group consisting of mono(meth)acrylates such as those described herein, di(meth)acrylates, tri(meth)acrylates, tetra(meth)acrylates such as those described herein, and mixtures thereof. Suitable mono(meth)acrylates may be selected from alkyl(meth)acrylates, cycloalkyl(meth)acrylates, benzyl(meth)acrylate, phenyl(meth)acrylate (including phenoxyalkyl(meth)acrylates such as phenoxyethyl acrylate), cyclic trimethylolpropane formal acrylate, tetrahydrofurfuryl acrylate, aliphatic urethane(meth)acrylates, and alkoxylated (particularly ethoxylated or propoxylated) compounds thereof.Suitable di(meth)acrylates include, but are not limited to, ethylene glycol diacrylate; ethylene glycol dimethacrylate; 1,4-butanediol diacrylate; 1,4-butanediol dimethacrylate; 1,3-butanediol diacrylate; 1,3-butanediol dimethacrylate; 2-methyl-1,3-propanediol diacrylate; 3-methyl-1,5-pentanediol diacrylate; 2-butyl-2-ethyl-1,3-propanediol diacrylate; 1,6-hexanediol diacrylate; 1,6-hexanediol dimethacrylate; neopentyl glycol diacrylate; neopentyl glycol dimethacrylate; 1,9-nonanediol diacrylate; 1,9-nonanediol dimethacrylate; 1,10-decanediol diacrylate; 1,10-decanediol dimethacrylate; alkoxylated (especially ethoxylated and propoxylated) 1,6-hexanediol diacrylates. Diol diacrylate; propoxylated neopentyl glycol diacrylate; ethoxylated 2-methyl-1,3-propanediol diacrylate; tricyclodecane dimethanol diacrylate; diethylene glycol diacrylate; diethylene glycol dimethacrylate; dipropylene glycol diacrylate; triethylene glycol diacrylate; triethylene glycol dimethacrylate; tripropylene glycol diacrylate; tripropylene glycol dimethacrylate; tetraethylene glycol diacrylate; tetraethylene glycol dimethacrylate; polyethylene glycol 200 / 400 / 600 diacrylate; polyethylene glycol 200 / 400 / 600 dimethacrylate; ethoxylated (EO2 / EO3 / EO4 / EO10) bisphenol A diacrylate; and ethoxylated (EO2 / EO3 / EO4 / EO10) bisphenol A dimethacrylate. Particularly suitable tripropylene glycol diacrylate (CAS 42978-66-5) is sold under the name TPGDA by Allnex.

[0091]

[0090] For embodiments in which the top coating composition is applied by a non-contact fluid microdispensing process, particularly by an inkjet printing process, said top coating composition may further comprise conventional additives and ingredients such as, for example, wetting agents, defoamers, surfactants, (co)solvents, and mixtures thereof, used in the field of radiation curable inkjet.

[0092]

[0091] The top coating compositions described herein may further comprise one or more labeling substances or taggants and / or one or more machine-readable materials, such as those described for the radiation-curable coating compositions comprising the non-spherical magnetic or magnetizable pigment particles described herein, provided that the size of the substances, taggants, or machine-readable materials is suitable for the application process described herein.

[0093] The method for producing an optical effect layer (OEL) exhibiting one or more indicia (x30) comprises at least partially curing the one or more indicia (x30) and one or more areas of the coating layer (x10) beneath said one or more indicia (x30) with an LED curing unit (x50), and at least partially curing the coating layer (x10) with a curing unit (x60) emitting at least between 250 nm and 320 nm, requiring specific combinations to allow selective curing of the one or more indicia (x30) and the coating layer (x10) at different stages of the method. Accordingly, the mixture of photoreactive compounds of the radiation-curable coating composition in step a) and the mixture of compounds of the top-curable coating composition in step b) are selected according to any one of the eight embodiments (first to eighth embodiments) described herein, as summarized in the table hereinafter entitled "Summary Embodiments."

[0094] According to the first embodiment i), the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts and one or more α-hydroxyketone compounds; and The mixture of compounds of the top-curable coating composition in step b) includes any one of the compounds described in i-1) to i-5), i'-1) to i'-5), i''-1) to i''-5), and i'''-1) to i'''-5) (i.e., the mixture of compounds of the top-curable coating composition in step b) includes any one of i-1) one or more sulfonium salts and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds, i-2) one or more thioxanthone compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds, i-3) one or a plurality of anthracene compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or a benzyl ketal compound and / or one or more oxime ester compounds which are 2,2-dimethoxy-1,2-diphenylethan-1-one, i-4) a plurality of naphthalene compounds and one or more anthracene compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or a benzyl ketal compound and / or one or more oxime ester compounds which are 2,2-dimethoxy-1,2-diphenylethan-1-one, or i-5) a plurality of coumarin compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or a benzyl ketal compound and / or one or more oxime ester compounds which are 2,2-dimethoxy-1,2-diphenylethan-1-one, The one or more iodonium salts of the radiation-curable coating composition of step a) of the first embodiment are preferably those listed in Table T1, and the one or more α-hydroxyketone compounds of the radiation-curable coating composition of step a) of the first embodiment are preferably those listed in Table T2, and The one or more sulfonium salts of the top curable coating composition of step b) of the first embodiment are preferably those listed in Table T3, the one or more thioxanthone compounds of the top curable coating composition of step b) of the first embodiment are preferably those listed in Table T4, the one or more anthracene compounds of the top curable coating composition of step b) of the first embodiment are preferably those listed in Table T5, the one or more naphthalene compounds of the top curable coating composition of step b) of the first embodiment are preferably those listed in Table T6, the one or more coumarin compounds of the top curable coating composition of step b) of the first embodiment are preferably those listed in Table T7, the one or more acylphosphine compounds of the top curable coating composition of step b) of the first embodiment are preferably those listed in Table T8, the one or more glyoxylate compounds of the top curable coating composition of step b) of the first embodiment are preferably those listed in Table T9, and the one or more oxime ester compounds of the top curable coating composition of step b) of the first embodiment are preferably those listed in Table T10. [Table 1] JPEG2025525893000007.jpg216149 [Table 2] [Table 3] [Table 4] JPEG2025525893000011.jpg24149 [Table 5] [Table 6] [Table 7] [Table 8] [Table 9] [Table 10]

[0095] According to the second embodiment ii), the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds for the top-curable coating composition in step b) includes any one of the compounds described in ii-1) to ii-5), ii'-1) to ii'-5), ii''-1) to ii''-5), and ii'''-1) to ii'''-5) (i.e., the mixture of compounds for the top-curable coating composition in step b) includes any one of the compounds described in ii-1) to ii-5), ii'-1) to ii'-5), ii''-1) to ii'' ...), ii-1) to ii-5), ii-2) one or more sulfonium salts and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds, ii-2) one or more thioxanthone compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds, ii ii-3) one or more anthracene compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds, ii-4) one or more naphthalene compounds and one or more anthracene compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds, or ii-5) one or more coumarin compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds, The one or more iodonium salts of the radiation-curable coating composition of step a) of the second embodiment are preferably those listed in Table T1, and The one or more sulfonium salts of the top curable coating composition of step b) of the second embodiment are preferably those listed in Table T3, the one or more thioxanthone compounds of the top curable coating composition of step b) of the second embodiment are preferably those listed in Table T4, the one or more anthracene compounds of the top curable coating composition of step b) of the second embodiment are preferably those listed in Table T5, the one or more naphthalene compounds of the top curable coating composition of step b) of the second embodiment are preferably those listed in Table T6, the one or more coumarin compounds of the top curable coating composition of step b) of the second embodiment are preferably those listed in Table T7, the one or more acylphosphine compounds of the top curable coating composition of step b) of the second embodiment are preferably those listed in Table T8, the one or more glyoxylate compounds of the top curable coating composition of step b) of the second embodiment are preferably those listed in Table T9, and the one or more oxime ester compounds of the top curable coating composition of step b) of the second embodiment are preferably those listed in Table T10.

[0096] According to the third embodiment iii), The mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts and one or more α-hydroxyketone compounds, and the mixture of compounds of the top-curable coating composition of step b) comprises any of the compounds set forth in iii-1) to iii-5), iii'-1) to iii'-5), iii''-1) to iii''-5), and iii'''-1) to iii'''-5) (i.e., the mixture of compounds of the top-curable coating composition of step b) comprises any of the compounds set forth in iii-1) to iii-5), iii'-1) to iii'-5), iii''-1) to iii'''-5), and iii'''-1) to iii'''-5). iii-1) a benzyl ketal compound and / or one or more oxime ester compounds, which are a plurality of sulfonium salts and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one; iii-2) a benzyl ketal compound and / or one or more oxime ester compounds, which are a plurality of sulfonium salts and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one; iii-3) a benzil ketal compound and / or one or more oxime ester compounds which are one or more anthracene compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one; iii-4) a benzil ketal compound and / or one or more oxime ester compounds which are one or more naphthalene compounds and one or more anthracene compounds and one or more acylphosphine compounds and / or one or more iii-5) one or more coumarin compounds and one or more iodonium salts, and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds, and Preferably, the one or more sulfonium salts of the radiation-curable coating composition of step a) of the third embodiment are those listed in Table T11 and the one or more α-hydroxyketone compounds of the radiation-curable coating composition of step a) of the third embodiment are those listed in Table T2, and The one or more sulfonium salts of the top curable coating composition of step b) of the third embodiment are as set out in Table T3, the one or more thioxanthone compounds and the one or more iodonium salts of the top curable coating composition of step b) of the third embodiment are preferably as set out in Tables T4 and T1, the one or more anthracene compounds of the top curable coating composition of step b) of the third embodiment are preferably as set out in Table T5, the one or more naphthalene compounds of the top curable coating composition of step b) of the third embodiment are preferably as set out in Table T6, and the one or more naphthalene compounds of the top curable coating composition of step b) of the third embodiment are preferably as set out in Table T7. The coumarin compound(s) and the iodonium salt(s) of the top curable coating composition are preferably those set out in Tables T7 and T1, the acylphosphine compound(s) of the top curable coating composition of step b) of the third embodiment are preferably those set out in Table T8, the glyoxylate compound(s) of the top curable coating composition of step b) of the third embodiment are preferably those set out in Table T9, and the oxime ester compound(s) and the iodonium salt(s) of the top curable coating composition of step b) of the third embodiment are preferably those set out in Tables T10 and T1. [Table 11] JPEG2025525893000019.jpg188149 JPEG2025525893000020.jpg107149

[0097] According to a fourth embodiment iv), the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds for the top-curable coating composition in step b) includes any one of the compounds described in iv-1) to iv-5), iv'-1) to iv'-5), iv''-1) to iv''-5), and iv'''-1) to iv'''-5) (i.e., the mixture of compounds for the top-curable coating composition in step b) includes any one of the compounds described in iv-1) to iv-5), iv'-1) to iv'-5), iv''-1) to iv''-5), and iv'''-1) to iv'''-5) (i.e., the mixture of compounds for the top-curable coating composition in step b) includes any one of the compounds described in iv-1) one or more sulfonium salts and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds, iv-2) one or more thioxanthone compounds and one or more iodonium salts and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzyl ketal compounds and / or one or more oxime ester compounds, iv- iv-3) one or more anthracene compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds, iv-4) one or more naphthalene compounds and one or more anthracene compounds and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds, or iv-5) one or more coumarin compounds and one or more iodonium salts and one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds, and the one or more sulfonium salts of the radiation-curable coating composition of step a) of the fourth embodiment are those set forth in Table T11, and The one or more sulfonium salts of the top curable coating composition of step b) of the fourth embodiment are preferably those listed in Table T3, the one or more thioxanthone compounds and the one or more iodonium salts of the top curable coating composition of step b) of the fourth embodiment are preferably those listed in Table T4 and Table T1, the one or more anthracene compounds of the top curable coating composition of step b) of the fourth embodiment are preferably those listed in Table T5, the one or more naphthalene compounds of the top curable coating composition of step b) of the fourth embodiment are preferably those listed in Table T6, The one or more coumarin compounds and one or more iodonium salts of the top curable coating composition of step b) of the fourth embodiment are preferably those listed in Tables T7 and T1, the one or more acylphosphine compounds of the top curable coating composition of step b) of the fourth embodiment are preferably those listed in Table T8, the one or more glyoxylate compounds of the top curable coating composition of step b) of the fourth embodiment are preferably those listed in Table T9 and the one or more oxime ester compounds of the top curable coating composition of step b) of the fourth embodiment are preferably those listed in Table T10.

[0098] According to the fifth embodiment v), the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts and one or more α-hydroxyketone compounds; the mixture of compounds of the top-curable coating composition of step b) comprises any one of the compounds set forth in v-1) to v-5), v'-1) to v'-5), v''-1) to v''-5), and v'''-1) to v'''-5) (i.e., the mixture of compounds of the top-curable coating composition of step b) comprises v-1) one or more sulfonium salts, v-2) one or more thioxanthone compounds, v-3) one or more anthracene compounds, v-4) one or more naphthalene compounds and one or more anthracene compounds, or v-5) one or more coumarin compounds); and The one or more iodonium salts of the radiation-curable coating composition of step a) of the fifth embodiment are preferably those listed in Table T1, and the one or more α-hydroxyketone compounds of the radiation-curable coating composition of step a) of the fifth embodiment are preferably those listed in Table T2, and The one or more sulfonium salts of the top curable coating composition of step b) of the fifth embodiment are preferably those listed in Table T3, the one or more thioxanthone compounds of the top curable coating composition of step b) of the fifth embodiment are preferably those listed in Table T4, the one or more anthracene compounds of the top curable coating composition of step b) of the fifth embodiment are preferably those listed in Table T5, the one or more naphthalene compounds of the top curable coating composition of step b) of the fifth embodiment are preferably those listed in Table T6 and the one or more coumarin compounds of the top curable coating composition of step b) of the fifth embodiment are preferably those listed in Table T7.

[0099] According to the sixth embodiment vi), the mixture of photoreactive compounds of the radiation-curable coating composition in step a) comprises one or more iodonium salts and a benzyl ketal compound that is 2,2-diethoxyacetophenone; the mixture of compounds of the top-curable coating composition in step b) comprises any one of the compounds set forth in vi-1) to vi-5), vi'-1) to vi'-5), vi''-1) to vi''-5), and vi'''-1) to vi'''-5) (i.e., the mixture of compounds of the top-curable coating composition in step b) comprises vi-1) one or more sulfonium salts, vi-2) one or more thioxanthone compounds, vi-3) one or more anthracene compounds, vi-4) one or more naphthalene compounds and one or more anthracene compounds, or vi-5) one or more coumarin compounds); and The one or more iodonium salts of the radiation-curable coating composition of step a) of the sixth embodiment are preferably those listed in Table T1, and The one or more sulfonium salts of the top curable coating composition of step b) of the sixth embodiment are preferably those listed in Table T3, the one or more thioxanthone compounds of the top curable coating composition of step b) of the sixth embodiment are preferably those listed in Table T4, the one or more anthracene compounds of the top curable coating composition of step b) of the sixth embodiment are preferably those listed in Table T5, the one or more naphthalene compounds of the top curable coating composition of step b) of the sixth embodiment are preferably those listed in Table T6 and the one or more coumarin compounds of the top curable coating composition of step b) of the sixth embodiment are preferably those listed in Table T7.

[0100] According to the seventh embodiment vii), the mixture of photoreactive compounds of the radiation-curable coating composition in step a) comprises one or more sulfonium salts and one or more α-hydroxyketone compounds; the mixture of compounds of the top-curable coating composition in step b) comprises any one of the compounds set forth in vii-1) to vii-5), vii'-1) to vii'-5), vii''-1) to vii''-5), and vii'''-1) to vii'''-5) (i.e., the mixture of compounds of the top-curable coating composition in step b) comprises vii-1) one or more sulfonium salts, vii-2) one or more thioxanthone compounds and one or more iodonium salts, vii-3) one or more anthracene compounds, vii-4) one or more naphthalene compounds and one or more anthracene compounds, or vii-5) one or more coumarin compounds and one or more iodonium salts); and Preferably, the one or more sulfonium salts of the radiation-curable coating composition of step a) of the seventh embodiment are those listed in Table 11, and the one or more α-hydroxyketone compounds of the radiation-curable coating composition of step a) of the seventh embodiment are those listed in Table T2, and The one or more sulfonium salts of the top curable coating composition of step b) of the seventh embodiment are as set out in Table T3, the one or more thioxanthone compounds and the one or more iodonium salts of the top curable coating composition of step b) of the seventh embodiment are preferably as set out in Tables T4 and T1, the one or more anthracene compounds of the top curable coating composition of step b) of the seventh embodiment are preferably as set out in Table T5, the one or more naphthalene compounds of the top curable coating composition of step b) of the seventh embodiment are preferably as set out in Table T6, and the one or more coumarin compounds and the one or more iodonium salts of the top curable coating composition of step b) of the seventh embodiment are preferably as set out in Tables T7 and T1.

[0101] According to the eighth embodiment viii), the mixture of photoreactive compounds of the radiation-curable coating composition in step a) comprises one or more sulfonium salts and a benzyl ketal compound that is 2,2-diethoxyacetophenone; the mixture of compounds of the top-curable coating composition in step b) comprises any one of the compounds set forth in viii-1) to viii-5), viii'-1) to viii'-5), viii''-1) to viii''-5), and viii'''-1) to viii'''-5) (i.e., the mixture of compounds of the top-curable coating composition in step b) comprises viii-1) one or more sulfonium salts, viii-2) one or more thioxanthone compounds and one or more iodonium salts, viii-3) one or more anthracene compounds, viii-4) one or more naphthalene compounds and one or more anthracene compounds, or viii-5) one or more coumarin compounds and one or more iodonium salts); and The one or more sulfonium salts of the radiation-curable coating composition of step a) of the eighth embodiment are as set forth in Table 11; The one or more sulfonium salts of the top curable coating composition of step b) of the eighth embodiment are as set out in Table T3, the one or more thioxanthone compounds and the one or more iodonium salts of the top curable coating composition of step b) of the eighth embodiment are preferably as set out in Tables T4 and T1, the one or more anthracene compounds of the top curable coating composition of step b) of the eighth embodiment are preferably as set out in Table T5, the one or more naphthalene compounds of the top curable coating composition of step b) of the eighth embodiment are preferably as set out in Table T6, and the one or more coumarin compounds and the one or more iodonium salts of the top curable coating composition of step b) of the eighth embodiment are preferably as set out in Tables T7 and T1.

[0102] For mixtures of top-curable coating compositions (i-2), ii-2), v-2) and vi-2), i'-2), ii'-2), v'-2) and vi'-2), and i''-2), ii''-2), v''-2) and vi''-2), and i'''-2), ii'''-2), v'''-2) and vi'''-2)) of the first, second, fifth, and sixth embodiments described herein and comprising one or more thioxanthone compounds described herein, said top-curable coating compositions further comprise one or more iodonium salts, preferably those set forth in Table T1.

[0103] For the mixtures of top-curable coating compositions (i-3) to viii-3), i'-3) to viii'''-3) and i''-3) to viii''-3) and i'''-3) to viii'-3)) of step b) of the first, second, third, fourth, fifth, sixth, seventh, and eighth embodiments described herein and comprising one or more anthracene compounds described herein, said top-curable coating compositions may further comprise one or more iodonium salts, preferably those set forth in Table T1, and / or one or more sulfonium salts, preferably those set forth in Tables T3 and / or T11.

[0104] For the mixtures of top-curable coating compositions of step b) of the first, second, third, fourth, fifth, sixth, seventh, and eighth embodiments (i-4) to viii-4) and i'-4) to viii'-4) and i'''-4) to viii''-4) and i'''-4) to viii'''-4)) as described herein and comprising one or more anthracene compounds as described herein and one or more naphthalene compounds as described herein, said top-curable coating compositions may further comprise one or more iodonium salts, preferably those set forth in Table T1, and / or one or more sulfonium salts, preferably those set forth in Tables T3 and / or T11.

[0105] For the mixtures of top-curable coating compositions of step b) of the first, second, third, fifth and sixth embodiments (i-5), ii-5), v-5) and vi-5), and i'-5), ii'-5), v'-5), and vi'-5) and i''-5), (ii''-5), v''-5) and vi''-5), and i'''-5), ii'''-5), v'''-5) and vi'''-5)), as described herein and comprising one or more coumarin compounds as described herein, said top-curable coating compositions may further comprise one or more iodonium salts, preferably those set forth in Table T1. Overview of the first to eighth embodiments described in this specification [Table 12] JPEG2025525893000022.jpg204149 JPEG2025525893000023.jpg213149 JPEG2025525893000024.jpg183149 JPEG2025525893000025.jpg98149

[0106] The method described herein includes, partially simultaneously with or subsequent to step b) described herein, step c) of at least partially curing one or more indicia (x30) and one or more areas of the coating layer (x10) beneath the one or more indicia (x30) with light-emitting diode (LED) curing units (x50). In contrast to medium-pressure mercury lamps, which have emission bands in the UV-A, UV-B, and UV-C regions of the electromagnetic spectrum, UV-LED lamps emit radiation in the UV-A and / or visible (Vis) regions, for example, in the range of about 350 nm to about 470 nm. Furthermore, current UV-LED and Vis-LED lamps emit quasi-monochromatic radiation, i.e., they emit radiation only at one wavelength, for example, 365 nm, 385 nm, 395 nm, 405 nm, or 450 nm. Step c) of at least partially curing the one or more indicia (x30) is carried out by exposing them to UV light emitted from an LED curing unit (x50), preferably at one or more wavelengths between about 355 nm and about 415 nm, more preferably at 365 nm and / or 385 nm and / or 395 nm. "Partially simultaneously" means that both steps are carried out partially simultaneously, i.e., the time for carrying out each step partially overlaps. In the context described herein, if curing is carried out partially simultaneously with application step b), it must be understood that curing is effective after the formation of the one or more indicia (x30) before full or partial curing. Step c) should be carried out after step b) described herein, and the time between the two steps is preferably less than 10 seconds, more preferably less than 5 seconds.

[0107] The method described herein comprises, after step c) described herein, a step d) of exposing the coating layer (x10) to a magnetic field of a magnetic field generator described herein in order to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles. According to one embodiment, step d) is performed in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles described herein. According to another embodiment, step d) is performed in order to biaxially orient at least a portion of the platelet-shaped magnetic or magnetizable pigment particles, preferably in order to biaxially orient at least a portion of the platelet-shaped magnetic or magnetizable pigment particles so as to have both an X-axis and a Y-axis substantially parallel to the substrate surface. For embodiments in which the method described herein comprises a step of exposing the coating layer (x10) to a magnetic field of a magnetic field generator described herein in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles, the coating layer (x10) may be subsequently exposed to said magnetic field generator more than once.

[0108] For embodiments of the methods described herein in which the step of exposing the coating layer (x10) to a magnetic field of a magnetic field generating device described herein is performed to orient at least a portion of the magnetic or magnetizable pigment particles in a biaxial direction, it is required that at least a portion of the non-spherical magnetic or magnetizable pigment particles described herein consist of platelet-shaped magnetic or magnetizable pigment particles having X and Y axes defining the particle's major planes of extension. In contrast to needle-shaped pigment particles, which can be considered one-dimensional particles, platelet-shaped pigment particles have X and Y axes defining the particle's major planes of extension. In other words, platelet-shaped pigment particles may be considered two-dimensional particles due to the large aspect ratio of their dimensions, as can be seen in FIG. 1. As shown in FIG. 1, platelet-shaped pigment particles can be considered two-dimensional structures in which the dimensions X and Y are substantially greater than the dimension Z. Platelet-shaped pigment particles are also referred to in the art as ellipsoidal particles or flakes. Such pigment particles may be described by a major axis X, corresponding to the longest dimension across the pigment particle, and a second axis Y, perpendicular to X, that also lies within said pigment particle.

[0109]

[0108] During the magnetization orientation step described herein of the non-spherical magnetic or magnetizable pigment particles, the substrate (x20) supporting the coating layer (x10) may be placed on a non-magnetic support plate (x40) made of one or more non-magnetic materials.

[0110]

[0109] During the magnetization orientation step of the magnetic or magnetizable pigment particles described herein, the position of the magnetic field generators is not limited and depends on the selection and design of the magnetization orientation pattern to be created. Depending on the selection and design of the magnetization orientation pattern to be created, the magnetic field generators (B1, B2, B3) may be placed under the substrate (x20) or above the coating layer (x10).

[0111]

[0110] In contrast to uniaxial orientation, in which magnetic or magnetizable pigment particles are oriented such that only their major axes are constrained by a magnetic field, performing biaxial orientation means that the platelet-shaped magnetic or magnetizable pigment particles are oriented such that their two main axes are constrained. That is, each platelet-shaped magnetic or magnetizable pigment particle can be considered to have a major axis in the plane of the pigment particle and an orthogonal minor axis in the plane of the pigment particle. The major and minor axes of the platelet-shaped magnetic or magnetizable pigment particles are each oriented in accordance with the magnetic field. Effectively, this results in platelet-shaped magnetic pigment particles being adjacent to each other in close proximity, with gaps between them, and substantially parallel to each other. In other words, biaxial orientation aligns the faces of the platelet-shaped magnetic or magnetizable pigment particles such that the faces of the pigment particles are oriented substantially parallel to the faces of adjacent (all-around) platelet-shaped magnetic or magnetizable pigment particles. The magnetic field generating devices and methods described herein allow for biaxial orientation of the platelet-shaped magnetic or magnetizable pigment particles described herein such that they form sheet-like structures with their X and Y axes preferably substantially parallel to the substrate (x20) surface and are flattened in said two dimensions.

[0112]

[0111] Suitable magnetic field generating devices for uniaxially orienting the magnetic or magnetizable pigment particles described herein include, but are not limited to, dipole magnets, quadrupole magnets, and combinations thereof. The following devices are provided herein as illustrative examples:

[0113]

[0112] An optical effect known as a flip-flop effect (also referred to in the art as a switch effect) includes a first printed portion and a second printed portion separated by a transition, with pigment particles aligned parallel to a first surface in the first portion and pigment particles aligned parallel to a second surface in the second portion. Methods and magnets for producing this effect are disclosed, for example, in U.S. Patent Application Publication No. 2005 / 0106367 and EP 1 819 525.

[0114]

[0113] An optical effect known as the rolling bar effect, as disclosed in U.S. Patent Application Publication No. 2005 / 0106367, may also be produced. The "rolling bar" effect is based on pigment particle orientation that mimics a curved surface across the coating. The viewer sees a specular reflection zone that faces away from or towards the viewer when the image is tilted. The pigment particles are aligned in a curved manner, following either a convex curve (also referred to in the art as a negative curve orientation) or a concave curve (also referred to in the art as a positive curve orientation). Methods and magnets for producing the effect are disclosed, for example, in EP 2263806, EP 1674282, EP 2263807, WO 2004 / 007095, WO 2012 / 104098, and WO 2014 / 198905.

[0115]

[0114] An optical effect known as a Venetian blind effect may also be produced. The Venetian blind effect involves pigment particles oriented to impart visibility to the underlying substrate surface along a particular direction of observation, such that indicia or other features present on or in the substrate surface are apparent to the observer while they obstruct visibility along other directions of observation. Methods and magnets for producing this effect are disclosed, for example, in U.S. Pat. No. 8,025,952 and European Patent No. 1,819,525.

[0116]

[0115] An optical effect known as the moving rings effect may also be produced. The moving rings effect consists of optically illusory images of objects such as funnels, cones, bowls, circles, ellipses, and hemispheres that appear to move in any x- or y-direction depending on the tilt angle of the optical effect layer. Methods and magnets for producing this effect are disclosed, for example, in EP 1 710 756, U.S. Pat. No. 8,343,615, EP 2 306 222, EP 2 325 677, WO 2011 / 092502, U.S. Pat. App. No. 2013 / 0084411, WO 2014108404, and WO 2014 / 108303.

[0117]

[0116] Optical effects may also be produced that give the optical impression of a pattern of light and dark areas that moves when the effect is tilted. Methods and magnets for producing said effects are disclosed, for example, in WO 2013 / 167425.

[0118]

[0117] Optical effects may also be produced that give the optical impression of loop-shaped bodies with varying sizes upon slope of the effect. Methods and magnets for producing these optical effects are disclosed, for example, in WO 2017 / 064052, WO 2017 / 080698 and WO 2017 / 148789.

[0119]

[0118] The optical impression of one or more loop-shaped bodies that change shape when tilting the optical effect layer may also be produced. Methods and magnets for producing said effect are disclosed, for example, in WO 2018 / 054819.

[0120]

[0119] An optical effect may also be produced that gives the optical impression of a moving and rotating lunar crescent when tilted. Methods and magnets for producing said effect are disclosed, for example, in WO 2019 / 215148.

[0121]

[0120] Optical effects may be produced that give the optical impression of a loop-shaped body that changes size and shape when tilted. Methods and magnets for producing said effect are disclosed, for example, in co-pending PCT patent application WO 2020 / 052862.

[0122]

[0121] The optical effect producing the optical impression of ortho-parallax may be produced, namely in this case in the form of bright reflective vertical bars which move longitudinally when the substrate is tilted about a horizontal / latitudinal axis, or which move horizontally / latitudinal when the substrate is tilted about a longitudinal axis. Methods and magnets for producing said effect are disclosed, for example, in co-pending PCT patent application International Application No. PCT / EP2020 / 052265.

[0123]

[0122] An optical effect may be produced that gives the optical impression of one loop-shaped body surrounded by one or more loop-shaped bodies, said one or more loop-shaped bodies having their shape and / or their brightness that change when tilted. Methods and magnets for producing said effect are disclosed, for example, in co-pending PCT patent application International Application No. PCT / EP2020 / 054042.

[0124]

[0123] An optical effect may be produced which produces the optical impression of multiple dark spots and multiple bright spots that move and / or appear and / or disappear diagonally when the substrate is tilted, as well as moving and / or appearing and / or disappearing diagonally when the substrate is tilted. Methods and magnets for producing said effect are disclosed, for example, in International Patent Applications WO2021 / 083808A1 and WO2021 / 083809A1.

[0125]

[0124] The magnetic field generating devices described herein may be at least partially embedded in a non-magnetic supporting matrix made of one or more non-magnetic materials.

[0126]

[0125] The non-magnetic materials of the non-magnetic support plate (x40) described herein and the non-magnetic support matrix described herein are preferably independently selected from the group consisting of non-magnetic metals and engineering plastics and polymers, including, but not limited to, aluminum, aluminum alloys, brass (an alloy of copper and zinc), titanium, titanium alloys, and austenitic steel (i.e., non-magnetic steel). Engineering plastics and polymers include, but are not limited to, polyaryletherketone (PAEK) and its derivatives, polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK), and polyetherketoneetherketoneketone (PEKEKK); polyacetal, polyamide, polyester, polyether, copolyetherester, polyimide, polyetherimide, high density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMWPE), polybutylene terephthalate (PBT), polypropylene, acrylonitrile butadiene styrene (ABS) copolymer, fluorinated and perfluorinated polyethylene, polystyrene, polycarbonate, polyphenylene sulfide (PPS), and liquid crystal polymers. Preferred materials are PEEK (polyetheretherketone), POM (polyoxymethylene), PTFE (polytetrafluoroethylene), Nylon (polyamide), and PPS.

[0127]

[0126] The magnetic field generating devices described herein may comprise a magnetic plate carrying one or more reliefs, imprints or incisions. WO 2005 / 002866 and WO 2008 / 046702 are examples of such imprinted magnetic plates.

[0128]

[0127] The magnetic field generating device described in this specification may be a soft magnetic plate supporting one or more indicia in the form of recesses and / or protrusions, or a soft magnetic plate containing one or more spaces in the shape of one or more indicia, and the orientation step is carried out by forming an assembly of a substrate (x20) supporting a coating layer (x10) on the soft magnetic plate, and moving said assembly through the inhomogeneous magnetic field of a static magnetic field generating device (x40) in order to orient at least a portion of the platelet-shaped magnetic or magnetizable pigment particles in two axial directions, as described in WO 2018 / 019594 and WO 2018 / 033512.

[0129]

[0128] The magnetic field generating device described in this specification may be a magnetic assembly (x30) comprising a soft magnetic plate comprising one or more spaces for accommodating one or more dipole magnets, and comprising one or more recesses and / or one or more protrusions forming one or more continuous loop-shaped indicia and / or one or more discontinuous loop-shaped indicia, as described in WO 2020 / 025218, or a magnetic assembly comprising a soft magnetic plate comprising one or more spaces and one or more dipole magnets arranged in the one or more spaces, and one or more dipole magnets facing one or more pairs of two dipole magnets arranged at a regular interval with one or more spaces arranged below the one or more spaces and / or soft magnetic plate, as described in WO 2020 / 025482.

[0130]

[0129] Magnetic field generating devices suitable for biaxially orienting the platelet-shaped magnetic or magnetizable pigment particles described herein are not limited.

[0131]

[0130] A particularly preferred apparatus for orienting pigment particles in two directions is disclosed in EP-A-2 157 141. Upon movement of a substrate supporting a coating layer comprising pigment particles, the apparatus disclosed in EP-A-2 157 141 provides a dynamic magnetic field that causes the pigment particles to change direction and rapidly vibrate until both of their major axes (X and Y) are substantially parallel to the substrate surface, i.e. the pigment particles rotate and flatten in said two dimensions into a stable sheet-like formation with their X and Y axes substantially parallel to the substrate surface.

[0132] Another particularly preferred device for orienting pigment particles biaxially includes a linear permanent magnet Halbach array, i.e., a device comprising a plurality of magnets with different magnetization directions and a cylinder arrangement. A detailed description of Halbach permanent magnets is provided by ZQ Zhu and D. Howe (Halbach permanent magnet machines and applications: a review, IEE. Proc. Electric Power Appl., 2001, 148, pp. 299-308). The magnetic field produced by such a Halbach array has the property that it is concentrated on one side while weakening to nearly zero on the other side. Linear Halbach arrays are disclosed, for example, in WO 2015 / 086257 and WO 2018 / 019594, and Halbach cylinder arrangements are disclosed in EP 3224055.

[0133] Another particularly preferred device for biaxially orienting pigment particles is a rotary magnet, which includes a disk-shaped rotary magnet or magnetic field generator that is magnetized substantially along its diameter. Suitable rotary magnets or magnetic field generators are described in U.S. Patent Application Publication No. 2007 / 0172261, which generate a radially symmetric, time-varying magnetic field, enabling dual orientation of magnetic or magnetizable pigment particles in an uncured coating composition. These magnets or magnetic field generators are driven by a shaft (or spindle) connected to an external motor. Chinese Patent No. 102529326 discloses an example of a device including a rotary magnet that may be suitable for biaxially orienting magnetic or magnetizable pigment particles. In a preferred embodiment, the device suitable for biaxially orienting magnetic or magnetizable pigment particles is a shaftless disk-shaped rotary magnet or magnetic field generator restrained in a housing made of a nonmagnetic, preferably nonconductive, material, and driven by one or more coils of magnet wire wound around the housing. Examples of such shaft-less disk-shaped rotary magnets or magnetic field generators are disclosed in WO 2015 / 082344, WO 2016 / 026896, and WO 2018 / 141547.

[0134]

[0133] Another particularly preferred apparatus for biaxially orienting pigment particles is shown in Figure 3A and comprises: a) at least a first set (S1) and a second set (S2), each of the first and second sets (S1, S2) comprising a first bar dipole magnet having a magnetic axis oriented substantially parallel to the substrate during magnetization orientation, and two bar dipole magnets having magnetic axes oriented substantially perpendicular to the substrate; and b) a third pair of bar dipole magnets (P1) having magnetic axes oriented substantially parallel to the substrate, such as those disclosed in co-pending European Patent Application No. 20176506.2.

[0135]

[0134] The method described herein comprises, partially simultaneously with or after step d) described herein, step e) of at least partially curing the coating layer (x10) in curing units (x60) emitting at least between 250 nm and 320 nm.

[0136] The method described herein comprises, partially simultaneously with or after step d) described herein, a step e) of at least partially curing the coating layer (x10) in curing units (x60) radiating at least between 250 nm and 320 nm. By "partially simultaneously" it is meant that both steps are carried out partially simultaneously, i.e. the times of carrying out each step partially overlap. In the context described herein, it must be understood that if the curing is carried out partially simultaneously with the application step c), the curing takes effect after orientation of the non-spherical magnetic or magnetizable pigment particles in the coating layer (x10) before full or partial curing.

[0137]

[0136] According to one embodiment, for example, as shown in Figures 2A-1 and 2A-2, the method described herein comprises the following steps: a step a) of applying onto the surface of a substrate (x20) a radiation-curable coating composition comprising non-spherical magnetic or magnetizable pigment particles as described herein; After step a), step b) of applying a top coating composition in the form of one or more indicia (x30) onto the coating layer (x10) as described herein, partially simultaneously with or after step b), step c) of at least partially curing one or more indicia (x30) and one or more areas of the coating layer (x10) beneath said one or more indicia (x30) with an LED curing unit (x50) as described herein; after step c), a step d) of exposing the coating layer (x10) to a magnetic field of a magnetic field generator (B1) in areas of the coating layer (x10) that are not under the one or more indicia (x30) to orient at least a portion of the magnetic or magnetizable pigment particles described herein, wherein step d) may be performed to orient at least a portion of the magnetic or magnetizable pigment particles described herein uniaxially (FIG. 2A-1), biaxially (FIG. 2A-2), biaxially and then uniaxially (two steps, not shown), or simultaneously biaxially and uniaxially (one step, not shown); Partially simultaneously with or after step d), step e) of at least partially curing the coating layers (x10) in curing units (x60) emitting at least between 250 nm and 320 nm as described herein.

[0138]

[0137] According to one embodiment, the method described herein further comprises a step of exposing the coating layer (x10) to a magnetic field of a magnetic field generating device in order to orient at least a portion of the magnetic or magnetizable pigment particles, said step may be carried out after step b) or partially simultaneously and before step c).

[0139] For example, according to one embodiment shown in FIG. 2B, the method described herein comprises the following steps: a) applying a radiation-curable coating composition comprising non-spherical magnetic or magnetisable pigment particles as described herein onto the surface of a substrate (x20); After step a), step b) of applying a top coating composition in the form of one or more indicia (x30) onto the coating layer (x10) described herein, after or partially simultaneously with step b), exposing the coating layer (x10) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step may be carried out to orient at least a portion of the magnetic or magnetizable pigment particles described herein uniaxially (FIG. 2B), biaxially (not shown), biaxially and then uniaxially (two steps, not shown), or simultaneously biaxially and uniaxially (one step, not shown), After step b) and the orientation step with the magnetic field generator (B1), step c) of at least partially curing the one or more indicia (x30) and one or more areas of the coating layer (x10) below said one or more indicia (x30) with an LED curing unit (x50) as described herein, after step c), a step d) of exposing the coating layer (x10) to a magnetic field of a second magnetic field generator (B2) in areas of the coating layer (x10) not under the one or more indicia (x30) to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step d) may be performed to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles described herein (FIG. 2B), to biaxially orient (not shown), to biaxially and then uniaxially orient (two steps, not shown), or to simultaneously biaxially and uniaxially orient (one step, not shown); and Partially simultaneously with or after step d), step e) of at least partially curing the coating layers (x10) in curing units (x60) emitting at least between 250 nm and 320 nm as described herein.

[0140]

[0139] According to another embodiment, the method described herein further comprises a step of exposing the coating layer (x10) to a magnetic field of a magnetic field generating device in order to orient at least a portion of the magnetic or magnetizable pigment particles, said step may be carried out after step a) and before step b).

[0141] For example, according to one embodiment shown in Figures 2C / 2D / 2E / 2J / 2K, the method described herein comprises the following steps: a) applying a radiation-curable coating composition comprising non-spherical magnetic or magnetizable pigment particles as described herein onto the surface of a substrate (x20); after step a), exposing the coating layer (x10) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the magnetic or magnetizable pigment particles, said step may be carried out to orient at least a portion of the magnetic or magnetizable pigment particles described herein uniaxially (Figures 2C and D), biaxially (Figure 2E), biaxially and then uniaxially (two steps, Figures 2J and 2K) or simultaneously biaxially and uniaxially (one step, not shown), Step b) of applying a top coating composition in the form of one or more indicia (x30) onto the coating layer (x10) described herein, partially simultaneously with or after the orientation step in the magnetic field generating device (B1), After step b), step c) of at least partially curing one or more indicia (x30) and one or more areas of the coating layer (x10) below said one or more indicia (x30) with an LED curing unit (x50) as described herein, after step c), a step d) of exposing the coating layer (x10) to a magnetic field of a second magnetic field generator (B2, Fig. 2C / 2E), or a third magnetic field generator (B3, Fig. 2J / 2K), or a second and a third magnetic field generator (B2 then B3, Fig. 2D) in order to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step d) may be carried out in areas of the coating layer (x10) not under the plurality of indicia (x30) to uniaxially orient (Fig. 2C / 2E / 2J / 2K), to biaxially orient (not shown), to biaxially and then uniaxially orient (two steps, Fig. 2D), or to simultaneously biaxially and uniaxially orient (one step, not shown) at least a portion of the magnetic or magnetizable pigment particles described herein; and Partially simultaneously with or after step d), step e) of at least partially curing the coating layers (x10) in curing units (x60) emitting at least between 250 nm and 320 nm as described herein.

[0142] For example, according to one embodiment shown in Figures 2F / 2G / 2H / 2I, the method described herein comprises the following steps: a) applying a radiation-curable coating composition comprising non-spherical magnetic or magnetizable pigment particles as described herein onto a substrate (x20); after step a), a step a) of exposing the coating layer (x10) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step may be carried out to uniaxially orient (not shown), to biaxially orient (Figs. 2F / 2G / 2H / 2I), to biaxially and then uniaxially orient (two steps, not shown), or to simultaneously biaxially and uniaxially orient (one step, not shown) at least a portion of the magnetic or magnetizable pigment particles described herein, Step b) of applying a top coating composition in the form of one or more indicia (x30) onto the coating layer (x10) described herein, partially simultaneously with or after the orientation step in the magnetic field generating device (B1), after step b), exposing the coating layer (x10) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step may be carried out to orient at least a portion of the magnetic or magnetizable pigment particles described herein uniaxially (Figs. 2F / 2G / 2H / 2I), to orient biaxially (not shown), to orient biaxially and then uniaxially (two steps, not shown), or to orient biaxially and uniaxially simultaneously (one step, not shown); c) at least partially curing the one or more indicia (x30) and one or more areas of the coating layer (x10) below said one or more indicia (x30) with an LED curing unit (x50) as described herein, partially simultaneously with or after the step of exposing the coating layer (x10) to the magnetic field of the second magnetic field generating device (B2); after step c), a step d) of exposing the coating layer (x10) to a magnetic field of a third magnetic field generator (B3) in areas of the coating layer (x10) not under the one or more indicia (x30) to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step d) may be performed to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles described herein (FIGS. 2F / 2G / 2H / 2I), to biaxially orient (not shown), to biaxially and then uniaxially orient (two steps, not shown), or to simultaneously biaxially and uniaxially orient (one step, not shown); and Partially simultaneously with or after step d), step e) of at least partially curing the coating layer (x10) in curing units (x60) emitting at least between 250 nm and 320 nm as described herein.

[0143] The three following steps: step a) of applying a radiation-curable coating composition comprising non-spherical magnetic or magnetizable pigment particles as described herein onto the surface of a substrate (x20); step b) of applying, after step a), a top coating composition in the form of one or more indicia (x30) onto the coating layer (x10) as described herein; and step c) of at least partially curing the one or more indicia (x30) and one or more areas of the coating layer (x10) below said one or more indicia (x30) with an LED curing unit (x50) as described herein, partially simultaneously with or after step b), may be performed more than once, and the method comprising two or more steps a) to c) as described herein may further comprise, after the last step c), applying a radiation-curable coating composition to the surface of the substrate (x20); or in areas of the coating layer (x10) not under the plurality of indicia (x30), to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step d) may be carried out to orient at least a portion of the magnetic or magnetizable pigment particles described herein uniaxially, biaxially, biaxially and then uniaxially, or simultaneously biaxially and uniaxially; and, partially simultaneously with or after step d), further comprising step e) of at least partially curing the coating layer (x10) in a curing unit (x60) irradiating at least between 250 nm and 320 nm as described herein.

[0144] Alternatively, steps a) and b) may be interchanged, i.e. the method described herein consists of the following steps: applying a top coating composition onto a substrate surface in the form of one or more indicia described herein; applying a radiation curable coating composition comprising the non-spherical magnetic or magnetizable pigment particles described herein onto the one or more indicia; exposing the coating layer to a magnetic field of a magnetic field generating device to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step may be carried out to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles described herein, to biaxially orient, to biaxially and then uniaxially or to simultaneously biaxially and uniaxially orient; partially simultaneously with or after the orienting step, at least partially curing the one or more indicia and one or more areas of the coating layer (x10) on said one or more indicia (x30) with an LED curing unit (x50) as described herein; thereafter, exposing the coating layer (x10) to a magnetic field of a magnetic field generator in areas of the coating layer (x10) that are not on the one or more indicia (x30) to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step may be carried out to orient at least a portion of the magnetic or magnetizable pigment particles described herein uniaxially, to orient biaxially, or to orient biaxially and then uniaxially, or to orient biaxially and uniaxially simultaneously; and Partially simultaneously with or after the orientation step, at least partially curing the coating layers (x10) in curing units (x60) emitting at least between 250 nm and 320 nm as described herein.

[0145] Alternatively, the step of at least partially curing the coating layer (x10) with a curing unit (x60) emitting at least between 250 nm and 320 nm as described herein may be replaced with the step of at least partially curing the coating layer (x10) with an LED curing unit (x50) as described herein, provided that the second step of applying a top coating composition as described herein to the entire surface of the coating layer (x10) is carried out after the step of at least partially curing one or more indicia (x30) and one or more areas of the coating layer (x10) below said one or more indicia (x30) with an LED curing unit (x50). For example, the method as described herein comprises the following steps: applying a radiation-curable coating composition comprising the non-spherical magnetic or magnetizable pigment particles described herein onto a substrate surface; after said step, exposing the coating layer (x10) to a magnetic field of a magnetic field generator (B1) in order to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step may be carried out to uniaxially orient, to biaxially orient, to biaxially and then uniaxially or to simultaneously biaxially and uniaxially orient, preferably biaxially, at least a portion of the magnetic or magnetizable pigment particles described herein, Partially simultaneously with or after the orienting step in the magnetic field generating device (B1), applying a top coating composition as described herein in the form of one or more indicia (x30) onto the coating layer (x10) as described herein; after said step, exposing the coating layer (x10) to a magnetic field of a second magnetic field generator (B2) in order to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step may be carried out to orient at least a portion of the magnetic or magnetizable pigment particles described herein uniaxially, to orient biaxially and then uniaxially, or to orient biaxially and uniaxially simultaneously, preferably uniaxially; partially simultaneously with or after exposing the coating layers (x10) to the magnetic field of the second magnetic field generator (B2), at least partially curing the top coating composition and the lower coating layers (x10) with an LED curing unit (x50) as described herein; After the above step, applying a top coating composition as described herein onto the entire surface of the coating layer (x10) as described herein; after said step, exposing the coating layer (x10) to a magnetic field of a third magnetic field generator (B3) in order to orient at least a portion of the magnetic or magnetizable pigment particles described herein, said step may be carried out to orient at least a portion of the magnetic or magnetizable pigment particles described herein uniaxially, biaxially, or simultaneously biaxially and uniaxially, preferably uniaxially; and Partially simultaneously with or subsequent to the previous step, at least partially curing the top coating composition and coating layers (x10) with an LED curing unit (x50) as described herein.

[0146]

[0145] The present invention provides a method, as described herein, for producing a substrate (x20) comprising an optical effect layer (OEL) exhibiting one or more indicia (x30) thereon, as described herein, and the resulting one or more optical effect layers (OELs). The substrate (x20) described herein is preferably selected from the group consisting of paper or other fibrous materials (including woven and nonwoven fibrous materials) such as cellulose, paper-containing materials, glass, metal, ceramic, plastics and polymers, metallized plastics or polymers, composite materials, and mixtures or combinations of two or more thereof. Typical paper, paper-like, or other fibrous materials are composed of various fibers, including, but not limited to, abaca, cotton, linen, wood pulp, and mixtures thereof. As is well known to those skilled in the art, cotton and cotton / linen mixtures are preferred for banknotes, while wood pulp is commonly used in non-banknote security documents. According to other embodiments, the substrate (x20) described herein is based on plastics and polymers, metallized plastics or polymers, composite materials, and mixtures or combinations of two or more thereof. Suitable examples of plastics and polymers include polyolefins such as polyethylene (PE) and polypropylene (PP), including biaxially oriented polypropylene (BOPP), polyamides, polyesters such as poly(ethylene terephthalate) (PET), poly(1,4-butylene terephthalate) (PBT), and poly(ethylene 2,6-naphthoate) (PEN), and polyvinyl chloride (PVC). Spunbond olefin fibers, such as those sold under the trademark Tyvek®, may also be used as the substrate. Representative examples of plated plastics or polymers include the above-mentioned plastics or polymeric materials having continuous or discontinuous metals disposed on the surface. Representative examples of metals include, but are not limited to, aluminum (Al), chromium (Cr), copper (Cu), gold (Au), silver (Ag), alloys thereof, and combinations of two or more of the aforementioned metals. The metallization of the plastic or polymeric material may be carried out by an electrodeposition process, a high vacuum coating process, or a sputtering process.Representative examples of composite materials include, but are not limited to, multi-layer structures or laminates of paper and at least one plastic or polymeric material such as those described above, as well as plastic and / or polymer fibers incorporated into paper-like or fibrous materials such as those described above. Naturally, the substrate may contain further additives known to those skilled in the art, such as fillers, sizing agents, whitening agents, processing aids, reinforcing agents, or wet strength agents. When the OELs exhibiting one or more indicia (x30) made according to the present invention are used for decorative or cosmetic purposes, including, for example, nail lacquers, the OELs may also be made on other types of substrates, including animal or human nails, artificial nails, or other parts.

[0147]

[0146] Also described herein is a method for producing a security document, or a decorative element or decorative body, the method comprising: a) providing a security document, or a decorative element or decorative body; and b) providing one or more optical effect layers as described herein, in particular those obtained by the methods described herein, to be included in the security document, or decorative element or decorative body.

[0148]

[0147] When the OEL made according to the present invention is on a security document or article, the substrate may comprise printing, coating, or laser marked or laser perforated indicia, water gauges, anti-counterfeit threads, fibers, planchets, luminescent compounds, windows, foils, decals, and combinations of two or more thereof, for the purpose of further improving the security level and resistance of said security document or article to counterfeiting and illegal duplication. The substrate may also comprise one or more marking substances or identification additives and / or machine-readable substances (e.g., luminescent substances, UV / visible / IR absorbing substances, magnetic materials, and combinations thereof), for the same purpose of further improving the security level and resistance of said security document or article to counterfeiting and illegal duplication.

[0149]

[0148] If necessary, a primer layer may be applied to the substrate before step a). This may improve the quality or promote adhesion of the OELs described herein. Examples of such primer layers can be found in WO 2010 / 058026.

[0150]

[0149] In order to improve the stain resistance or chemical resistance and cleanliness, and thus the circulation life of the security document, article, or decorative element or object comprising the OEL obtained by the method described herein, or to modify their aesthetics (e.g., optical gloss), one or more protective layers may be applied on the OEL. If present, the one or more protective layers typically consist of a protective varnish. The protective varnish may be a radiation-curable composition, a heat-drying composition, or any combination thereof. Preferably, the one or more protective layers are a radiation-curable composition, more preferably a UV-Vis-curable composition. The protective layer is typically applied after formation of the OEL.

[0151] The present invention further provides an optical effect layer (OEL) exhibiting one or more indicia (x30) as described herein and prepared by the method described herein. The shape of the optical effect layer (OEL) as described herein may be continuous or discontinuous. According to one embodiment, the shape of the coating layer (x10) represents one or more indicia, dots, and / or lines, said indicia having the same shape as or different from one or more indicia (x30) consisting of the top coating composition as described herein.

[0152]

[0151] An OEL exhibiting one or more indicia (x30) described herein may be applied directly to a substrate on which it will remain permanently (such as for banknote applications). Alternatively, the optical effect layer may also be applied to a temporary substrate for fabrication purposes from which the OEL is subsequently removed. This may facilitate, for example, fabrication of the optical effect layer (OEL), particularly while the binder material is still in its fluid state. Subsequently, after curing the coating composition for fabrication of the OEL, the temporary substrate may be removed from the OEL.

[0153] Alternatively, in other embodiments, an adhesive layer may be present on one or more indicia (x30) or on the side of the substrate containing the OEL, said adhesive layer being present on the substrate opposite the side on which the OEL is provided or on the same side as the OEL, and on the OEL. Thus, an adhesive layer may be applied to the OEL or the substrate, and said adhesive layer may be applied after the curing step is completed. Such articles may be attached to various types of documents or other articles or goods without the need for machinery and printing and other processes involving significant efficiency. Alternatively, the substrates described herein containing the OEL described herein may be in the form of a transfer foil, which can be applied to a document or article in a separate transfer step. For this purpose, the substrate is provided with a release coating, on which the OEL is prepared as described herein. One or more adhesive layers may be applied to the optical effect layer thus prepared.

[0154] Also described herein are substrates comprising more than one, ie, two, three, four, etc., optical effect layers (OELs) obtained by the methods described herein.

[0155] Also described herein are articles, documents, in particular security documents, decorative elements and decorative bodies, comprising an optical effect layer (OEL) made according to the present invention. The article, in particular the security document, decorative element or decorative body may comprise more than one (e.g., two, three, etc.) OEL made according to the present invention.

[0156] As mentioned above, OELs made according to the present invention may be used for decorative purposes and to protect and authenticate security documents.

[0157]

[0156] Representative examples of decorative elements or objects include, but are not limited to, articles of luxury goods, cosmetic packaging, automotive parts, electronic / electrical appliances, furniture, and nails.

[0158]

[0157] Security documents include, but are not limited to, documents of value and goods of value. Representative examples of documents of value include, but are not limited to, banknotes, certificates, tickets, invoices, certificates, revenue stamps, and tax labels, agreements, etc., passports, identification cards, visas, driver's licenses, bank cards, credit cards, transaction cards, access documents or cards, admission tickets, public transport tickets, academic diplomas or entitlements, etc., preferably identity documents such as banknotes, identity documents, entitlement documents, driver's licenses, and credit cards. The term "goods of value" particularly refers to packaging materials for cosmetics, dietary supplements, medicines, alcohol, tobacco products, beverages or food, electrical / electronic products, textiles, or jewelry, i.e., items that are protected from counterfeiting and / or illegal duplication to ensure the authenticity of the package contents, such as for pharmaceutical products. Examples of these packaging materials include, but are not limited to, labels, such as authentication brand labels, tamper-evident labels, and seals. Without limiting the scope of the present invention, it is pointed out that the disclosed substrates, documents of value, and goods of value are given solely for illustrative purposes.

[0159]

[0158] Alternatively, the optical effect layer (OEL) described herein may be fabricated on a secondary substrate, such as, for example, a security thread, security stripe, foil, decal, window, or label, and then transferred to the security document in a separate step.

[0160]

[0159] Those skilled in the art may foresee some modifications from the specific embodiments described above without departing from the spirit of the present invention, and such modifications are encompassed by the present invention.

[0161]

[0160] Additionally, all documents referenced throughout the specification are incorporated by reference in their entirety, as if fully set forth herein.

[0162] [Example] The present invention will now be described in more detail with reference to the following non-limiting examples. The following examples describe in more detail the preparation of an optical effect layer (OEL) exhibiting one or more indicia in the form of rectangles. Magnetic pigment particles (obtained from VIAVI Solutions, Santa Rosa, Calif., with a diameter d of about 10.7 μm) were used. 50 and seven-layered green-patina platelet-shaped optically variable magnetic pigment particles having a flake shape of about 1 μm thickness; and about 19 μm diameter d obtained from VIAVI Solutions (Santa Rosa, CA). 50 A screen printing composition comprising five layers of silver magnetic pigment particles having a flake shape and a thickness of about 1 μm has been prepared and is described in Table 1A. A top coating inkjet printing composition has been prepared and is described in Tables 1B1-1B4.

[0163] Preparation of the Composition

[0162] The screen-printed radiation-curable coating compositions used in step a) described herein were prepared independently by mixing the ingredients shown in Table 1A using a Dispermat CV-3 at room temperature and 2000 rpm for 10 minutes.

[0164]

[0163] The inkjet printing top coating compositions used in step b) described herein were prepared independently by mixing the ingredients shown in Tables 1B1 to 1B4 using Dispermat LC220-12 at room temperature and 1000 rpm for 10 minutes. Compounds shown in Table 1A and Tables 1B1 to 1B4 Omnicat 440: Bis(4-methylphenyl)iodonium hexafluorophosphate (IGM Resins) [CAS Nr 60565-88-0], Omnicat 250: (4-methylphenyl) [4-(2-methylpropyl) phenyl] iodonium hexafluorophosphate (IGM Resins) [CAS Nr 344562-80-7], Omnicat270: Tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate (IGM Resins) [CAS Nr 953084-13-4], SpeedCure 976: diphenyl[4-(phenylthio)phenyl]sulfonium-hexafluoroantimonate and (thiodi-4,1-phenylene)bis[diphenyl-sulfonium bis-hexafluoroantimonate (Lambson), Omnirad1173: 2-hydroxy-2-methylpropiophenone (IGM Resins) [CAS Nr 7473-98-5], GENOCURE * DEAP: 2,2-diethoxyacetophenone (Rahn) [CAS 6175-45-7], Omnirad380: phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide (IGM Resins) [CAS Nr 162881-26-7], Omnirad MBF: 2-oxo-2-phenylacetic acid methyl ester (IGM Resins) [CAS Nr 15206-55-0], Omnirad BDK: 2,2-dimethoxy-1,2-diphenylethan-1-one (IGM Resins) [CAS Nr 24650-42-8], SpeedCure8001: 4-Cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime) (Lambson) [CAS Nr 1206525-75-8], Omnirad ITX: Isopropyl-9H-thioxanthen-9-one (IGM Resins) [CAS Nr 5495-84-1], SpeedCure 7010: 1,3-di[[α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxy]-2,2-bis[[α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxymethylpropane (Lambson) [CAS Nr 1003567-83-6], ANTHRACURE® UVS1331: 9,10-dibutoxy-anthracene (Kawasaki Chemical Industries, Ltd.) [CAS Nr 76275-14-4], ANTHRACURE® ET2201: 9,10-diethoxy-naphthalene (Kawasaki Chemical Industries, Ltd.) [CAS Nr 27294-37-7], ESACURE3644: 3-(4-C10-C13-benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one (IGM Resins) [CAS Nr 2243703-91-3]

[0165]

[0164] The viscosities of the compositions were measured independently at 25°C with a Brookfield viscometer (model "DV-I Prime", spindle S21 at 100 rpm for the screen printing compositions of Table 1A and S00 at 60 rpm for the top coating inkjet printing compositions of Tables 1B1-1B4) and are shown in Tables 1A-1B and 2.

[0166] Preparation of optical effect layer (OEL)

[0165] Optical effect layers (OELs) were prepared according to the inventive methods (E1 to E165) using a polymer substrate (Guardian® from CCL Secure).

[0167] Tables 2A1-2A8 provide a summary of Examples E1-E154 prepared using the composition combinations disclosed in Tables 1A and 1B1-1B4 according to the method shown generally in FIG. 2A1, using magnetic field generator MD2 during the magnetic orientation step.

[0168]

[0167] Table 2B provides a summary of Examples E1-E2 and E155-E165 using a composition combination according to the first embodiment described herein, and using the method and magnetic field generators MD1, MD2, MD3 used during the magnetic orientation step as shown generally in Figures 2A-2K.

[0169]

[0168] Screen printing The radiation curable coating compositions described in Table 1A were independently applied by hand screen printing using a T90 screen onto a substrate (x20) (70 mm x 70 mm) to form a coating layer (x10) having the following dimensions: 25 mm x 25 mm and a thickness of approximately 20 μm.

[0170] Inkjet Printing The top coating compositions described in Tables 1B1-1B4 were printed at approximately 5 g / m by DOD inkjet printing using a Konica Minolta 1024i printhead (360 dpi) to form indicia having a rectangular shape with the following dimensions: 20 mm x 12 mm. 2 was granted independently.

[0171] In Figures 2A-1 and 2A-2, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), step b) of inkjet printing a respective inkjet printing top coating composition to form indicia (230); After step b), step c) of at least partially curing the indicia (230) and the area of the coating layer (210) below said indicia (230) with an LED curing unit (250); After step c), step d) of exposing the coating layer (210) to a magnetic field of a magnetic field generator (B1) (MD2; Fig. 2A-1) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), or to a magnetic field of a magnetic field generator (B1) (MD1; Fig. 2A-2) in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), Partially simultaneously with step d) (FIG. 2A-1) or after step d) (FIG. 2A-2), step e) of curing the coating layer (210) in a Hg curing unit (260) while maintaining a magnetic field generating device (B1) in the vicinity of the coating layer (210) to form an optical effect layer.

[0172] In FIG. 2B, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), step b) of inkjet printing a respective inkjet printing top coating composition to form indicia (230); After step b), exposing the coating layer (210) to a magnetic field of a first magnetic field generating device (B1, MD3) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles, partially simultaneously with step b), step c) at least partially curing the indicia (230) and the area of the coating layer (210) below said indicia (230) with an LED curing unit (250) while maintaining a first magnetic field generating device (B1) in the vicinity of the coating layer (210); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles described herein in the as yet uncured areas of the coating layer (210), Partially simultaneously with step d), step e) of curing the coating layer (210) in the Hg curing unit (260) while maintaining a second magnetic field generating device (B2) in the vicinity of the coating layer (210) to form an optical effect layer.

[0173] In FIG. 2C, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), subjecting the coating layer (210) to a magnetic field of a first magnetic field generating device (B1, MD3) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles, b) inkjet printing a respective inkjet printing top coating composition onto the coating layer (210) to form indicia (230) while maintaining the first magnetic field generating device (B1) in the vicinity of the coating layer (210) partially simultaneously with the step of exposing the coating layer (210) to the magnetic field of the first magnetic field generating device (B1); After step b), step c) of at least partially curing the indicia (230) and the area of the coating layer (210) below the indicia (230) with an LED curing unit (250) while maintaining the first magnetic field generating device (B1) in the vicinity of the coating layer (210); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), Partially simultaneously with step d), step e) of curing the coating layer (210) in the Hg curing unit (260) while maintaining a second magnetic field generating device (B2) in the vicinity of the coating layer (210) to form an optical effect layer.

[0174] In FIG. 2D, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), subjecting the coating layer (210) to a magnetic field of a first magnetic field generating device (B1, MD3) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles, b) inkjet printing a respective inkjet printing top coating ink composition onto the coating layer (210) to form indicia (230) while maintaining the first magnetic field generating device (B1) in the vicinity of the coating layer (210) partially simultaneously with the step of exposing the coating layer (210) to the magnetic field of the first magnetic field generating device (B1); partially simultaneously with step b), step c) at least partially curing the indicia (230) and the area of the coating layer (210) below said indicia (230) with an LED curing unit (250) while maintaining a first magnetic field generating device (B1) in the vicinity of the coating layer (210); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2, MD1) in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), After step d), subjecting the coating layer (210) to a magnetic field of a third magnetic field generator (B3, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), After the step of exposing the coating layer (210) to the magnetic field of the third magnetic field generating device (B3), step e) of curing the coating layer (210) in the Hg curing unit (260) to form an optical effect layer.

[0175] In FIG. 2E, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), subjecting the coating layer (210) to a magnetic field of a first magnetic field generator (B1, MD1) in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles, b) inkjet printing a respective inkjet printing top coating composition onto the coating layer (210) to form indicia (230) after exposing the coating layer (210) to the magnetic field of a first magnetic field generating device (B1); After step b), step c) of at least partially curing the indicia (230) and the area of the coating layer (210) below said indicia (230) with an LED curing unit (250); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a second magnetic field generator (B2, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), Partially simultaneously with the step of exposing the coating layer (210) to the magnetic field of the second magnetic field generator (B2), step e) curing the coating layer (210) in the Hg curing unit (260) while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210) to form an optical effect layer.

[0176] In FIG. 2F, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), subjecting the coating layer (210) to a magnetic field of a first magnetic field generator (B1, MD1) in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles, b) inkjet printing a respective jet-printed top-coating ink composition onto the coating layer (210) to form indicia (230) after exposing the coating layer (210) to the magnetic field of a first magnetic field generating device (B1); After step b), subjecting the coating layer (210) to a magnetic field of a second magnetic field generator (B2, MD3) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles, Partially simultaneously with step b) of exposing the coating layer (210) to the magnetic field of the second magnetic field generator (B2), step c) of at least partially curing the indicia (230) and the area of the coating layer (210) below the indicia (230) with an LED curing unit (250) while maintaining the second magnetic field generator (B2) in the vicinity of the coating layer (210); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), Partially simultaneously with the step of exposing the coating layer (210) to the magnetic field of the third magnetic field generator (B3), step e) of curing the coating layer (210) in the Hg curing unit (260) while maintaining the third magnetic field generator (B3) in the vicinity of the coating layer (210) to form an optical effect layer.

[0177] In FIG. 2G, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), subjecting the coating layer (210) to a magnetic field of a first magnetic field generator (B1, MD1) in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles, b) inkjet printing a respective inkjet printing top coating composition onto the coating layer (210) to form indicia (230) after exposing the coating layer (210) to the magnetic field of a first magnetic field generating device (B1); After step b), subjecting the coating layer (210) to a magnetic field of a second magnetic field generator (B2, MD3) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles, c) at least partially curing the indicia (230) and the area of the coating layer (210) below the indicia (230) with an LED curing unit (250) while maintaining the second magnetic field generating device (B2) in the vicinity of the coating layer (210) partially simultaneously with the step of exposing the coating layer (210) to the magnetic field of the second magnetic field generating device (B2); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), After step d), step e) of curing the coating layer (210) in a Hg curing unit (260) to form an optical effect layer.

[0178]

[0177] In Figure 2H, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), subjecting the coating layer (210) to a magnetic field of a first magnetic field generator (B1, MD1) in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles, b) inkjet printing a respective inkjet printing top coating composition onto the coating layer (210) to form indicia (230) after exposing the coating layer (210) to the magnetic field of the first magnetic field generating device (B1); After step b), subjecting the coating layer (210) to a magnetic field of a second magnetic field generator (B2, MD3) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles, a step c) of at least partially curing the indicia (230) and the area of the coating layer (210) below the indicia (230) with an LED curing unit (250) after the step of exposing the coating layer (210) to the magnetic field of the second magnetic field generator (B2); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the areas of the coating layer 210 that have not yet been hardened, Partially simultaneously with step d), step e) of curing the coating layer (210) in the Hg curing unit (260) while maintaining a third magnetic field generating device (B3) in the vicinity of the coating layer (210) to form an optical effect layer.

[0179] In FIG. 2I, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), subjecting the coating layer (210) to a magnetic field of a first magnetic field generator (B1, MD1) in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles, b) inkjet printing a respective inkjet printing top coating composition onto the coating layer (210) to form indicia (230) after exposing the coating layer (210) to the magnetic field of the first magnetic field generating device (B1); After step b), subjecting the coating layer (210) to a magnetic field of a second magnetic field generator (B2, MD3) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles, a step c) of at least partially curing the indicia (230) and the area of the coating layer (210) below the indicia (230) with an LED curing unit (250) after the step of exposing the coating layer (210) to the magnetic field of the second magnetic field generator (B2); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), After step (d), step e) of curing the coating layer (210) in a Hg curing unit (260) to form an optical effect layer.

[0180] In FIG. 2J, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), subjecting the coating layer (210) to a magnetic field of a first magnetic field generator (B1, MD1) in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles, After the step of exposing the coating layer (210) to the magnetic field of the first magnetic field generator (B1), exposing the coating layer (210) to the magnetic field of a second magnetic field generator (B2, MD3) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles; b) inkjet printing a respective inkjet printing top coating composition onto the coating layer (210) to form indicia (230) while maintaining the second magnetic field generating device (B2) in the vicinity of the coating layer (210) partially simultaneously with the step of exposing the coating layer (210) to the magnetic field of the second magnetic field generating device (B2); c) at least partially curing the indicia (230) and the area of the coating layer (210) below the indicia (230) with an LED curing unit (250) while maintaining the second magnetic field generating device (B2) in the vicinity of the coating layer (210) partially simultaneously with the step of exposing the coating layer (210) to the magnetic field of the second magnetic field generating device (B2); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), Partially simultaneously with step d), step e) of curing the coating layer (210) in the Hg curing unit (260) while maintaining a third magnetic field generating device (B3) in the vicinity of the coating layer (210) to form an optical effect layer.

[0181] In FIG. 2K, the method included the following steps: Step a) (not shown) of screen printing a respective screen-printing radiation-curable coating composition onto a substrate (220) to form a coating layer (210); After step a), subjecting the coating layer (210) to a magnetic field of a first magnetic field generator (B1, MD1) in order to biaxially orient at least a portion of the magnetic or magnetizable pigment particles, After the step of exposing the coating layer (210) to the magnetic field of the first magnetic field generator (B1), exposing the coating layer (210) to the magnetic field of a second magnetic field generator (B2, MD3) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles; b) inkjet printing an inkjet top coating printing composition onto the coating layer (210) to form indicia (230), after exposing the coating layer (210) to the magnetic field of a second magnetic field generating device (B2); After step b), step c) of at least partially curing the indicia (230) and the area of the coating layer (210) below said indicia (230) with an LED curing unit (250); After step c), a step d) of exposing the coating layer (210) to a magnetic field of a third magnetic field generator (B3, MD2) in order to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles in the not yet cured areas of the coating layer (210), Partially simultaneously with step d), step e) of curing the coating layer (210) and the indicia (230) in the Hg curing unit (260) while maintaining a third magnetic field generating device (B3) in the vicinity of the coating layer (210) to form an optical effect layer.

[0182] Magnetic orientation of screen printing compositions

[0181] A step of exposing the coating layer (x10) to a magnetic field from a magnetic field generating device described below was carried out separately to orient at least a portion of the magnetic or magnetizable pigment particles contained in the coating layer consisting of the screen-printed radiation-curable coating composition.

[0183] Magnetic field generator MD1 for biaxial alignment (shown in Figure 3A) The magnetic field generating device MD1 used to orient at least a portion of the magnetic or magnetizable pigment particles in a biaxial direction comprises: a) a first rod-shaped dipole magnet (371) and two second rod-shaped dipole magnets (372) a and 372 b ) and a first set (S1) including a first bar-shaped dipole magnet (371) and a second bar-shaped dipole magnet (372) a and 372 b ), and b) a second set (S2) including a third bar-shaped dipole magnet (373 a and 373 b ) pair (P1).

[0184]

[0183] The first and second sets (S1, S2) of first bar-shaped dipole magnets (371) and the second sets (S1, S2) of second bar-shaped dipole magnets (372) a and 372 b ) and a pair (P1) of third rod-shaped dipole magnets (373 a and 373 b The outermost surfaces of the layers were flush with each other.

[0185]

[0184] Third rod-shaped dipole magnet (373 a ) is connected to the second rod-shaped dipole magnet (372) of the first set (S1) to form a line. a ) and a second set (S2) of second rod-shaped dipole magnets (372 a ) was aligned with the third rod-shaped dipole magnet (373 b ) is connected to the second rod-shaped dipole magnet (372) of the first set (S1) to form a line. b ) and a second set (S2) of second rod-shaped dipole magnets (372 b ) was aligned.

[0186] The first bar-shaped dipole magnets (371) of the first and second sets (S1, S2) had the following dimensions: a first thickness (L1) of 5 mm, a first length (L4) of 60 mm, and a first width (L5) of 40 mm. The second bar-shaped dipole magnets (372) of the first and second sets (S1, S2) a and 372 b Each of the pair (P1) of third rod-shaped dipole magnets (373a and 373b) had the following dimensions: a second thickness (L2) of 10 mm, a second length (L6) of 40 mm, and a second width (L7) of 10 mm. Each of the pair (P1) of third rod-shaped dipole magnets (373a and 373b) had the following dimensions: a third thickness (L3) of 10 mm, a third length (L8) of 20 mm, and a third width (L9) of 10 mm.

[0187]

[0186] The first bar-shaped dipole magnet (371) of the first set (S1) and the second bar-shaped dipole magnet (372) of the first set (S1) a and 372 b) are aligned to form a row, and a first bar dipole magnet (371) of the second set (S2) and a second bar dipole magnet (372) of the second set (S2) are aligned to form a row. a and 372 b ) were aligned to form a row. For each set (S1, S2) and each row described herein, a first rod-shaped dipole magnet (371) and two second rod-shaped dipole magnets (372) were aligned to form a row. a and 372 b ) were spaced apart by a second distance (d2) of 2 mm. For each line described herein, a third rod-shaped dipole magnet (373 a and 373 b ) and two second rod-shaped dipole magnets (372 a ) were spaced apart by a third distance (d3) of 2 mm.

[0188]

[0187] The first rod-shaped dipole magnets (371) of the first and second sets (S1, S2) had magnetic axes oriented substantially parallel to the substrate (320), the first rod-shaped dipole magnets (371) of the first set (S1) had a magnetic direction opposite to the magnetic direction of the first rod-shaped dipole magnets (371) of the second set (S2), and were spaced apart by a first distance (d1) of 24 mm (corresponding to the sum of the third length (L8) and the two third distances (d3)).

[0189]

[0188] Two second rod-shaped dipole magnets (372) of the first and second sets (S1, S2) a and 372 b The second rod-shaped dipole magnet (372) of the first set (S1) had a magnetic axis oriented substantially perpendicular to the first plane and substantially perpendicular to the substrate (320). a The south pole of the second rod-shaped dipole magnet (372) faces the first plane and the substrate (320). b The north pole of the first bar-shaped dipole magnet (371) of the first set (S1) faces the substrate (320), and the north pole of the first bar-shaped dipole magnet (372) of the first set (S1) faces the second bar-shaped dipole magnet (372) of the first set (S1). b ) of the second set (S2) was directed toward the second rod-shaped dipole magnet (372 aThe north pole of the second rod-shaped dipole magnet (372) of the second set (S2) faces the first plane and the substrate (320). b The south pole of the first bar dipole magnet (371) of the second set (S2) faces the substrate (320), and the north pole of the first bar dipole magnet (372) of the second set (S2) faces the second bar dipole magnet (373). a ) was heading towards.

[0190]

[0189] Third rod-shaped dipole magnet (373 a ) is connected to the south pole of the second rod-shaped dipole magnet (372) of the first set (S1). a ) and the second rod-shaped dipole magnet (372 a ) has a south pole facing the substrate (320), and a third rod-shaped dipole magnet (373 b The north pole of the second rod-shaped dipole magnet (372) of the first set (S1) is b ) and the second rod-shaped dipole magnet (372 b ) has a north pole facing the substrate (320).

[0191]

[0190] The first and second sets (S1, S2) of first rod-shaped dipole magnets (371), the first and second sets (S1, S2) of second rod-shaped dipole magnets (373) a and 373 b ), and a pair (P1) of third rod-shaped dipole magnets (372 a and 372 b ) was made of NdFeB N42 and embedded in a non-magnetic support matrix (not shown) made of polyoxymethylene (POM) having the following dimensions: 115 mm x 115 mm x 12 mm.

[0192] During magnetic orientation, the substrate (320) supporting the coating layer (310) was placed on a non-magnetic support plate made of POM with the coating layer (310) facing the environment to form an assembly, the non-magnetic support plate (340) having the following dimensions: 180 mm x 130 mm x 2 mm and including a centrally aligned opening (48 mm x 48 mm) with the coating layer (310) facing the magnetic field generator (300). The assembly was moved back and forth three times near and above the magnetic field generator (300) at a distance of approximately 2 mm from the top surface of the device.

[0193] Magnetic field generator MD2 for uniaxial alignment The magnetic field generator MD2 used to uniaxially orient at least a portion of the magnetic or magnetizable pigment particles included a rod-shaped dipole magnet having a length of about 30 mm, a width of about 24 mm, and a thickness of about 6 mm, said rod-shaped dipole magnet being embedded in a matrix made of POM and having the following dimensions: 40 mm x 40 mm x 15 mm. The N-S magnetic axis of the rod-shaped dipole magnet was parallel to the substrate (320) surface and parallel to its width. The rod-shaped dipole magnet was made of NdFeB N42.

[0194]

[0193] During magnetic orientation, the substrate (320) supporting the coating layer (310) was placed on the non-magnetic support plate made of POM with the coating layer (310) facing the environment to form an assembly. The assembly was placed near and on top of a magnetic field generator such that the substrate (320) was approximately 6 mm from the top surface of a rod-shaped dipole magnet.

[0195] Magnetic field generator MD3 for uniaxial alignment (shown in Figure 3B) 6A of WO 2021 / 083809 discloses a magnetic field generator MD3 used for uniaxially orienting at least a portion of magnetic or magnetizable pigment particles, comprising a first magnetic field generator (330) embedded in a first square support matrix (332) and a second magnetic field generator (340) comprising a second dipole magnet (341) embedded in a second square support matrix (342), the second magnetic field generator (340) being positioned below the first magnetic field generator (330), the first magnetic field generator (330) being positioned between the substrate (320) supporting the coating layer (310) and the second magnetic field generator (340). The first magnetic field generator (330) and the second magnetic field generator (340) are positioned centrally relative to each other.

[0196]

[0195] The first magnetic field generating device (330) has nine parallel straight lines α i (α 1~9 ) and nine parallel lines β j (β 1~9 41 first dipole magnets (331) each having their centers positioned on the intersection of a grid containing 1~41 ) and the line α i (α 1~9 ) are parallel to each other, and the line β j (β 1~9 ) are parallel to each other, and the line α i is the line β j The nine lines α i (α 1~9 ) were evenly spaced, and adjacent lines were separated by a distance of 2.5 mm. i (α 1 / 3 / 5 / 7 / 9 ) includes five first dipole magnets and four wires α i (α 2 / 4 / 6 / 8 ) is the total number of first dipole magnets is 41 (331 1~41 ) contained four first dipole magnets. Nine wires β j (β 1~9 ) were evenly spaced, with the proximity lines separated by a distance of 2.5 mm. As shown in Figure 3B, the first dipole magnet (331 1~41) were arranged on grid intersections, some of which did not include a first dipole magnet.

[0197]

[0196] 41 first dipole magnets (331 1~41 The first dipole magnet (331) was cylindrical with the following dimensions: 2 mm (A4, diameter) x 2 mm (A5, length) and was made of NdFeB N45. 1~41 ) are all magnetized in the length (A5) direction, as shown by the arrows S → N in FIG. 3B, and are parallel to the surface of the substrate (320) and all point in the same direction along a straight line α i The first magnetic field generator (330) had a magnetic axis oriented parallel to the (α1 to α9) axes. The first magnetic field generator (330) had a vector sum H1 that was substantially parallel to the surface of the substrate (320).

[0198]

[0197] The first square support matrix (332) of the first magnetic field generator (330) has the following dimensions: 50 mm x 50 mm x 3 mm, is made of polyoxymethylene (POM), and contains 41 first dipole magnets (331 1~41 ) and the recesses are configured to hold the 41 first dipole magnets (331 1~41 ) and, as a result, the 41 first dipole magnets (331 1~41 The top surface of the first square support matrix (332) was flush with the top surface of the first square support matrix (332). The second dipole magnet (341) of the second magnetic field generator (340) was a square dipole magnet with the following dimensions: 30 mm (B4) x 30 mm (B5) x 2 mm (B3) and was made of NdFeB N52. The second dipole magnet (341) had a north-south magnetic axis substantially parallel to the substrate (320) surface. The second magnetic field generator (340) had a vector sum H2 (corresponding to the magnetic axis of the second dipole magnet (341)) substantially parallel to the substrate (320).

[0199]

[0198] The second square support matrix (342) of the second magnetic field generating device (340) had the following dimensions: 50 mm x 50 mm x 2 mm, was made of polyoxymethylene (POM) and included a recess / hole for holding the second dipole magnet (341), said recess / hole having the same shape and dimensions as the second dipole magnet (341) (i.e., 30 mm (B4) x 30 mm (B5) x 2 mm (B3)), so that the top and bottom surfaces of the second dipole magnet (341) were flush with the top and bottom surfaces of the second square support matrix (342).

[0200]

[0199] The top surface of the first square support matrix (332) of the first magnetic field generator (330) (41 first dipole magnets (331) 1~41 The distance (h1) between the upper surface of the second dipole magnet (341) of the second magnetic field generator (340) and the surface of the substrate (320) facing the magnetic assembly (300) was 1.5 mm. The distance (h2) between the upper surface of the second dipole magnet (341) of the second magnetic field generator (340) and the lowermost surface of the square support matrix (332) of the first magnetic field generator (330) was 0 mm, i.e., the first (330) and second (340) magnetic field generators were in direct contact.

[0201] Curing Unit The following units were used in the preparation of the optical effect layers (OEL): LED curing unit (x50): OmniCure® (Type, AC4 x 25 mm, 385 nm, 8 W / cm) with an exposure time of approximately 0.5 seconds 2 ) UV-LED lamp Hg curing unit (x60): 2 lamps: IST Metz GmbH iron-doped mercury lamp 200 W / cm² + mercury lamp 200 W / cm² 2 ; 2 passes at 100m / min

[0202]

[0201] After the curing step, each sample was rubbed with tissue paper to verify the curing of both the coating layer (x10) and the indicia (x30). [Table 13]

Table 14

Table 15

Table 18

Table 19

[0203] Photographs of the Example (Figs. 4A-H and Fig. 5)

[0202] Photographs of the optical effect layer (OEL) prepared as described above are shown in Figures 4A to 4H and Figure 5.

[0204]

[0203] The use of a specific combination of a mixture of photoreactive compounds of the radiation-curable coating composition in step a) and a mixture of compounds of the top-curable coating composition in step b) according to the first embodiment in the method according to the present invention, as shown by the photograph in Figure 4A; and the use of a specific combination according to the second embodiment, as shown by the photograph in Figure 4B; and the use of a specific combination according to the third embodiment, as shown by the photograph in Figure 4C; and the use of a specific combination according to the fourth embodiment, as shown by the photograph in Figure 4D; and the use of a specific combination according to the fifth embodiment, as shown by the photograph in Figure 4E; and the use of a specific combination according to the sixth embodiment, as shown by the photograph in Figure 4F; and the use of a specific combination according to the seventh embodiment, as shown by the photograph in Figure 4G; and the use of a specific combination according to the eighth embodiment, as shown by the photograph in Figure 4H, made it possible to produce an optical effect layer (OEL) that showed not only the dynamic movement of the rolling bar when the substrate was tilted due to the magnetization orientation of the particles in the magnetic field generating device (B1) but also indicia.

[0205] As shown by the photographs in Figure 5, the use of a particular combination of a mixture of photoreactive compounds of the radiation-curable coating composition in step a) according to a first embodiment of the method described in Figures 2A to 2K according to the present invention and a mixture of compounds of the top-curable coating composition in step b) made it possible to produce optical effect layers (OELs) showing indicia, as well as dynamic movement of the rolling bar when the substrate is tilted (see E1, E2 and E159), or bright areas around the indicia (see E155), or both the rolling bar (in the area outside the indicia) moving and / or appearing and / or disappearing when the substrate is tilted and multiple dark spots and multiple bright spots (in the area of the indicia) (see E156 to E158 and E160 to E165).

Claims

1. 1. A method for producing an optical effect layer (OEL), said OEL comprising a motif consisting of at least two areas of a single applied and cured layer comprising non-spherical magnetic or magnetisable pigment particles and exhibiting one or more indicia (x30) on a substrate (x20), the method comprising: a) applying a radiation-curable coating composition on a surface of a substrate (x20) comprising a mixture of non-spherical magnetic or magnetizable pigment particles, one or more cationically curable compounds, one or more radiation-curable compounds, and a photoreactive compound that does not absorb in the range of about 350 nm to about 470 nm, wherein the radiation-curable coating composition is in a first liquid state to form a coating layer (x10); b) after step a), at least partially applying a top coating composition onto the coating layer (x10), thus forming one or more areas of the coating layer (x10) below said one or more indicia (x30), said top coating composition being applied in the form of one or more indicia (x30), said top coating composition comprising one or more curable compounds and a mixture of compounds, at least one of said compounds absorbing in the range of about 350 nm to about 470 nm; c) partially simultaneously with or after step b), at least partially curing one or more indicia (x30) and one or more areas of the coating layer (x10) below said one or more indicia (x30) with LED curing units (x50) emitting between 350 nm and 470 nm; d) after step c), exposing the coating layer (x10) to a magnetic field of a magnetic field generator to orient at least a portion of the non-spherical magnetic or magnetizable pigment particles; e) partially simultaneously with or after step d), at least partially curing the coating layer (x10) in curing units (x60) emitting at least between 250 nm and 320 nm, The method, wherein the mixture of photoreactive compounds of the radiation curable coating composition of step a) and the mixture of compounds of the top curable coating composition of step b) are selected according to one of the following combinations: i) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts and one or more α-hydroxyketone compounds; The mixture of compounds of the top curable coating composition of step b) is i-1) The anion portion is SbF ６ － ;PF ６ － ; AsF ６ － ; F ４ B － ; (C ６ F ５ ) ４ B － ; (CF ３ SO ２ ) ３ C － ; (CF ３ ) SO ３ － ; (CH ３ C ６ H ４ ) SO ３ － ; (CF ３ ) CO ２ － ; (C ４ F ９ ) SO ３ － Or (C ４ F ９ ) CO ２ － and the cationic moiety is one or more sulfonium salts of which tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium; (9-oxo-9H-thioxanthen-2-yl)diphenyl-sulfonium; or mixtures thereof, and further comprises one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or benzyl ketal compounds and / or one or more oxime ester compounds, wherein the cationic moiety is 2,2-dimethoxy-1,2-diphenylethan-1-one; i-2) one or more thioxanthone compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; i-3) one or more anthracene compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; i-4) one or more naphthalene compounds and one or more anthracene compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or i-5) one or more coumarin compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or ii) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts and a benzil ketal compound that is 2,2-diethoxyacetophenone; The mixture of compounds of the top curable coating composition of step b) is ii-1) The anion portion is SbF ６ － ;PF ６ － ; AsF ６ － ; F ４ B － ; (C ６ F ５ ) ４ B － ; (CF ３ SO ２ ) ３ C － ; (CF ３ ) SO ３ － ; (CH ３ C ６ H ４ ) SO ３ － ; (CF ３ ) CO ２ － ; (C ４ F ９ ) SO ３ － Or (C ４ F ９ ) CO ２ － and the cationic moiety is one or more sulfonium salts of which tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium; (9-oxo-9H-thioxanthen-2-yl)diphenyl-sulfonium; or mixtures thereof, and further comprises one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or benzyl ketal compounds and / or one or more oxime ester compounds, wherein the cationic moiety is 2,2-dimethoxy-1,2-diphenylethan-1-one; ii-2) one or more thioxanthone compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; ii-3) one or more anthracene compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; ii-4) one or more naphthalene compounds and one or more anthracene compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; ii-5) one or more coumarin compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or iii) The mixture of photoreactive compounds in the radiation-curable coating composition of step a) is a mixture of photoreactive compounds in which the anionic moiety is SbF ６ － ;PF ６ － ; AsF ６ － ; F ４ B － ; (C ６ F ５ ) ４ B － ; (CF ３ SO ２ ) ３ C － ; (CF ３ ) SO ３ － ; (CH ３ C ６ H ４ ) SO ３ － ; (CF ３ ) CO ２ － ; (C ４ F ９ ) SO ３ － Or (C ４ F ９ ) CO ２ － and the cationic moiety is 4-(phenylthio)phenyldiphenyl-sulfonium; bis[4-(diphenylsulfonium)phenyl]sulfide; (4-methylphenyl)diphenyl-sulfonium; (3-methylphenyl)diphenyl-sulfonium; bis(4-methylphenyl)phenyl-sulfonium; [(4-(1,1-dimethylethyl)phenyl]diphenyl-sulfonium; bis[4-(1-methylethyl)phenyl]phenyl-sulfonium; [(4-(2-methylpropyl)phenyl]diphenyl-sulfonium; (4-methoxyphenyl)phenyl-sulfonium; (4-phenyl)diphenyl-sulfonium; 1-naphthalenyldiphenyl-sulfonium; tris(4-methylphenyl)-sulfonium; (4-bromophenyl)diphenyl-sulfonium; (4-iodophenyl)diphenyl-sulfonium; (4-fluorophenyl)diphenyl-sulfonium; (4-chlorophenyl)diphenyl-sulfonium; (4-phenoxyphenyl)diphenyl-sulfonium; (4'-methyl[1,1'-biphenyl]-4-yl)diphenyl-sulfonium; tris(4-propylphenyl)-sulfonium; Bis(4-butylphenyl)phenyl-sulfonium; Tris[4(1-methylethyl)phenyl]-sulfonium; S,S'-1,3-phenylenebis[S,S'-diphenyl]-sulfonium; (4-dodecylphenyl)diphenyl-sulfonium; (4-benzoylphenyl)diphenyl-sulfonium; Bis([1,1'-biphenyl]-4-yl)(4-methylphenyl)-sulfonium; Tris[4-[1,1-dimethylethyl)phenyl]-sulfonium; Triphenyl-sulfonium; 5-(4-methylphenyl)-dibenzothio phenium; 5-[4-(2-hydroxyethoxy)phenyl]-thianthrenium; 10-(4-methylphenyl)-9H-thioxanthenium; diphenyl[4-[[(4-phenylthiophenyl]thio]phenyl]-sulfonium; phenyl-bis[4-phenylthio)phenyl]-sulfonium; 5-[4-(phenylthio)phenyl]-thianthrenium; 5-[4-(phenylthio)phenyl]-dibenzothiophenium; 10-[4-(diphenylthio)phenyl]-9H-thioxanthenium; 5-phenyl-thianthrenium;10-phenyl-9H-thioxanthenium; 5-(4-methylphenyl)-thianthrenium; 5-[1,1'-biphenyl]-4-yl-thianthrenium; S,S'-(thiodi-4,1-phenylene)bis[S,S'-bis[4-(2-hydroxyethoxy)]phenyl]-sulfonium; or mixtures thereof, and one or more α-hydroxyketone compounds; The mixture of compounds of the top curable coating composition of step b) is iii-1) one or more sulfonium salts listed in i-1), and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; iii-2) one or more thioxanthone compounds and one or more iodonium salts, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; iii-3) one or more anthracene compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; iii-4) One or more naphthalene compounds and one or more anthracene compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or iii-5) one or more coumarin compounds and one or more iodonium salts, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or iv) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts listed in iii) and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds of the top curable coating composition of step b) is iv-1) one or more sulfonium salts listed in i-1), and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; iv-2) one or more thioxanthone compounds and one or more iodonium salts, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; iv-3) one or more anthracene compounds, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; iv-4) One or more naphthalene compounds and one or more anthracene compounds, and further one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or iv-5) one or more coumarin compounds and one or more iodonium salts, and further comprising one or more acylphosphine compounds and / or one or more glyoxylate compounds and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds and / or one or more oxime ester compounds; or v) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts and one or more α-hydroxyketone compounds; and The mixture of compounds of the top curable coating composition of step b) is v-1) one or more sulfonium salts listed under i-1); v-2) one or more thioxanthone compounds; v-3) one or more anthracene compounds; v-4) one or more naphthalene compounds and one or more anthracene compounds; or v-5) containing one or more coumarin compounds; or vi) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more of an iodonium salt and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds of the top curable coating composition of step b) is vi-1) one or more sulfonium salts listed under i-1); vi-2) one or more thioxanthone compounds; vi-3) one or more anthracene compounds; vi-4) one or more naphthalene compounds and one or more anthracene compounds; or vi-5) containing one or more coumarin compounds; or vii) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more of the sulfonium salts listed in iii) and one or more α-hydroxyketone compounds; and The mixture of compounds of the top curable coating composition of step b) is vii-1) one or more sulfonium salts listed under i-1); vii-2) one or more thioxanthone compounds and one or more iodonium salts; vii-3) one or more anthracene compounds; vii-4) one or more naphthalene compounds and one or more anthracene compounds; or vii-5) comprising one or more coumarin compounds and one or more iodonium salts; or viii) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more of the sulfonium salts listed in iii) and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds of the top curable coating composition of step b) is viii-1) one or more sulfonium salts listed under i-1); viii-2) one or more thioxanthone compounds and one or more iodonium salts; viii-3) one or more anthracene compounds; viii-4) one or more naphthalene compounds and one or more anthracene compounds; or viii-5) Contains one or more coumarin compounds and one or more iodonium salts.

2. 10. The method of claim 1, wherein the mixture of photoreactive compounds of the radiation-curable coating composition of step a) and the mixture of compounds of the top-curable coating composition of step b) are selected according to one of the following combinations: i') The mixture of photoreactive compounds in the radiation curable coating composition of step a) is a mixture of photoreactive compounds in which the anionic moiety is SbF ６ － ;PF ６ － ; AsF ６ － ; F ４ B － ; (C ６ F ５ ) ４ B － ; (CF ３ SO ２ ) ３ C － ; (CF ３ ) SO ３ － ; (CH ３ C ６ H ４ ) SO ３ － ; (CF ３ ) CO ２ － ; (C ４ F ９ ) SO ３ － Or (C ４ F ９ ) CO ２ － (Preferably SbF ６ － ;PF ６ － ; (CF ３ ) SO ３ － ; (C ４ F ９ ) SO ３ － ; F ４ B － Or (C ６ F ５ ) ４ B － ), and the cationic moiety is bis(4-dodecylphenyl)iodonium; bis[4-(1,1-dimethylethyl)phenyl]iodonium; (4-isopropylphenyl)(4-methylphenyl)iodonium; bis(4-methylphenyl)iodonium; (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium; bis(2,4-dimethylphenyl)]iodonium; bis(3,4-dimethylphenyl)]iodonium; (4-methylphenyl)(2,4,6-trimethylphenyl)iodonium; bis[(4-(2-methylphenyl)]iodonium; Bis(4-butylphenyl)iodonium; Bis(2,4,6-trimethylphenyl)iodonium; Bis(4-hexylylphenyl)iodonium; Bis(4-decylphenyl)iodonium; (4-decylphenyl)(4-undecylphenyl)iodonium; Bis(4-undecylphenyl)iodonium; Bis(4-tridecylphenyl)iodonium; Bis(4-tetradecylphenyl)iodonium; Bis(4-hexadecylphenyl)iodonium; Bis(4-heptadecylphenyl) Iodonium; Bis(4-octadecylphenyl)iodonium; (4-decylphenyl)(4-dodecylphenyl)iodonium; (4-decylphenyl)(4-tridecylphenyl)iodonium; (4-decylphenyl)(4-tetradecylphenyl)iodonium; (4-dodecylphenyl)(4-undecylphenyl)iodonium; (4-dodecylphenyl)(4-tridecylphenyl)iodonium; (4-dodecylphenyl)(4-tetradecylphenyl)iodonium; (4-tridecylphenyl)(4-undecylphenyl) )iodonium; (4-tetradecylphenyl)(4-undecylphenyl)iodonium; (4-tetradecylphenyl)(4-tridecylphenyl)iodonium; p-(octyloxyphenyl)phenyliodonium; [(4-[(2-hydroxytetradecyl)oxy]phenyl]phenyliodonium; bis(4-fluorophenyl)iodonium; (4-nitrophenyl)phenyliodonium; (4-nitrophenyl)(2,4,6-trimethylphenyl)iodonium; or mixtures thereof;and 2-hydroxy-2-methylpropiophenone; 2-hydroxy-4'-hydroxyethoxy-2-methylpropiophenone; 2-hydroxy-1-[4-[4-(1-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropan-1-one; (1-hydroxycyclohexyl)phenylmethanone; 2-hydroxy-1-[4-[4-(1-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropan-1-one; 1-[2,3-dihydro-1-[4-(1-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropan-1-one ar-(1-hydroxy-2-methyl-1-oxopropyl)(1-methylethenyl)-benzene homopolymer; α-(1,1-dimethyl-2-oxo-2-phenylethyl)-ω-hydroxy-poly(oxy-1,2-ethanediyl) (9CI); polymeric α-hydroxy-ketones and mixtures thereof; and The mixture of compounds of the top curable coating composition of step b) is i'-1) The anion portion is SbF ６ － 、 PF ６ － , (C ６ F ５ ) ４ B － , (CF ３ ) SO ３ － , or (C ４ F ９ ) SO ３ － wherein the cationic moiety is one or more sulfonium salts of which the cationic moiety is tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium; (9-oxo-9H-thioxanthen-2-yl)diphenyl-sulfonium; or mixtures thereof, and further ...anthen-2-yl)diphenyl-sulfonium; one or more acylphosphine compounds selected from the group consisting of bis(1,6-dimethoxybenzoyl)(1,4,4-trimethylpentyl)phosphine oxide; ethyl(3-benzoyl-2,4,6-trimethylbenzoyl)(phenyl)phosphinate; α,α',α''-1,2,3-propanetriyltris[ω-[[phenyl(1,4,6-trimethylbenzoyl)phosphinyl]oxy]-poly(oxy-1,2-ethanediyl) and mixtures thereof; and / or 2-oxo-2 one or more glyoxylate compounds selected from the group consisting of 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl 2-oxo-2-phenylacetate; α-(1-oxo-2-phenylacetyl)-ω-[(1-oxo-2-phenylacetyl)oxy]-poly(oxy-1,4-butanediyl) and mixtures thereof; and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or 5-[[4-(1-methylethyl)phenyl]thio]-1H -indene-1,2(3H)-dione 2-(O-acetyloxime); 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyloxime); 3-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-propanedione-2-(O-benzoyloxime); 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); 1-[9-ethyl-6-(1-methylbenzoyl)-9H-carbazol-3-yl]ethanone-1-(O-acetyloxime);3-cyclopentyl-1-[9-ethyl-6-(1-methylbenzoyl)-9H-carbazol-3-yl]-1-propanone-1-(O-acetyloxime); 1,8-bis(O-acetyloxime)-1,8-bis[9-(1-ethylhexyl)-6-nitro-9H-carbazol-3-yl]-1,8-octanedione; or a mixture thereof; i'-2) 2-isopropyl-9H-thioxanthen-9-one; 4-(1-methylethyl)-9H-thioxanthen-9-one; 2,4-diethyl-9H-thioxanthen-9-one; 2-chloro-9H-thioxanthen-9-one; 1-Chloro-4-propoxy-9H-thioxanthen-9-one; 1,3-di[[α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxy]-2,2-bis[[α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxymethylpropane; α-[2-[(9 -oxo-9H-thioxanthenyl)oxy]acetyl]-ω-[[2-[(9-oxo-9H-thioxanthenyl)oxy]acetyl]oxy]-poly(oxy-1,4-butanediyl; 2-[2-[1-[2-[[2-(9-oxothioxanthen-2-yl)oxyacetyl]amino]-3-[1-[2-(2-prop-2-enoyloxyethoxy)ethoxy]ethoxy]-2-[1-[2-(2-prop-2-enoyloxyethoxy)ethoxy]ethoxy] one or more thioxanthone compounds selected from the group consisting of α-[2-[(9-oxo-9H-thioxanthenyl)oxy]acetyl]-ω-[[2-[(9-oxo-9H-thioxanthenyl)oxy]acetyl]oxy]-poly(oxy-1,4-butanediyl); oligomeric and polymeric compounds thereof, and mixtures thereof, and further including one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); i'-3) One or more anthracene compounds selected from the group consisting of 9,10-diethoxy-anthracene; 9,10-dibutoxy-anthracene, and mixtures thereof, and further comprising one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); i'-4) A naphthalene compound which is 9,10-diethoxy-naphthalene, and one or more anthracene compounds selected from the group consisting of 9,10-diethoxy-anthracene; 9,10-dibutoxy-anthracene, and mixtures thereof, and further comprising one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); or i'-5) 3-(4-dodecylbenzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one; 3-(4-C １０ -C １３ -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one, and mixtures thereof, and further comprising one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); or ii') the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more of the iodonium salts listed in i') and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds of the top curable coating composition of step b) is ii'-1) One or more sulfonium salts listed in i'-1), and further one or more acylphosphine compounds listed in i'-1); and / or one or more glyoxylate compounds listed in i'-1); and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i'-1); ii'-2) one or more thioxanthone compounds listed in i'-2), and further comprising one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); ii'-3) One or more anthracene compounds listed in i'-3), and further comprising one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); ii'-4) one or more naphthalene compounds listed in i'-4) and one or more anthracene compounds listed in i'-4), and further one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); or ii'-5) one or more coumarin compounds listed in i'-5), and further one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); or iii') The mixture of photoreactive compounds in the radiation curable coating composition of step a) is a mixture of photoreactive compounds in which the anionic moiety is SbF ６ － ;PF ６ － ; (C ６ F ５ ) ４ B － ; (CF ３ ) SO ３ － Or (C ４ F ９ ) SO ３ － (Preferably SbF ６ － or PF ６ － ), the cationic moiety is 4-(phenylthio)phenyldiphenyl-sulfonium; bis[4-(diphenylsulfonium)phenyl]sulfide; (4-methylphenyl)diphenyl-sulfonium; bis(4-methylphenyl)phenyl-sulfonium; bis[4-(1-methylethyl)phenyl]phenyl-sulfonium; (4-methoxyphenyl)diphenyl-sulfonium; 1-naphthalenyldiphenyl-sulfonium; tris(4-methylphenyl)-sulfonium; (4 (4'-methyl[1,1'-biphenyl]-4-yl)diphenyl-sulfonium; 5-[4-(2-hydroxyethoxy)phenyl]-thianthrenium; S,S'-(thiodi-4,1-phenylene)bis[S,S'-bis[4-(2-hydroxyethoxy)]phenyl]-sulfonium; or a mixture thereof, and one or more sulfonium salts which are one or more of the α-hydroxyketone compounds listed under i'); and The mixture of compounds of the top curable coating composition of step b) is iii'-1) One or more sulfonium salts listed in i'-1), and further one or more acylphosphine compounds listed in i'-1); and / or one or more glyoxylate compounds listed in i'-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i'-1); iii'-2) one or more thioxanthone compounds listed in i'-2) and one or more iodonium salts listed in i'), and further one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); iii'-3) One or more anthracene compounds listed in i'-3), and further comprising one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); iii'-4) one or more naphthalene compounds listed in i'-4) and one or more anthracene compounds listed in i'-4), and further one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); or iii'-5) one or more coumarin compounds listed in i'-5) and one or more iodonium salts listed in i'), and further one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); or iv') the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more of the sulfonium salts listed in iii') and a benzyl ketal compound that is 2,2-diethoxyacetophenone; and The mixture of compounds of the top curable coating composition of step b) is iv'-1) One or more sulfonium salts listed in i'-1), and further one or more acylphosphine compounds listed in i'-1); and / or one or more glyoxylate compounds listed in i'-1); and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i'-1); iv'-2) one or more thioxanthone compounds listed in i'-2) and one or more iodonium salts listed in i'), and further one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); iv'-3) One or more anthracene compounds listed in i'-3), and further comprising one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); iv'-4) one or more naphthalene compounds listed in i'-4) and one or more anthracene compounds listed in i'-4), and further one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); or iv'-5) one or more coumarin compounds listed in i'-5) and one or more iodonium salts listed in i'), and further one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i'-1) and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one and / or one or more oxime ester compounds listed in i'-1); or v') the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts listed in i') and one or more α-hydroxyketone compounds listed in i'); and The mixture of compounds of the top curable coating composition of step b) is v'-1) one or more sulfonium salts listed in i'-1); v'-2) one or more thioxanthone compounds listed in i'-2); v'-3) one or more anthracene compounds listed in i'-3); v'-4) one or more naphthalene compounds listed in i'-4) and one or more anthracene compounds listed in i'-4); or v'-5) containing one or more coumarin compounds listed in i'-5); or vi') the mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises one or more of the iodonium salts listed in i') and a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is vi'-1) one or more sulfonium salts listed under i'-1); vi'-2) one or more thioxanthone compounds listed in i'-2); vi'-3) one or more anthracene compounds listed in i'-3); vi'-4) one or more naphthalene compounds listed in i'-4) and one or more anthracene compounds listed in i'-4); or vi'-5) containing one or more coumarin compounds listed in i'-5); or vii') the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts listed in iii') and one or more α-hydroxyketone compounds listed in i'); and The mixture of compounds of the top curable coating composition of step b) is vii'-1) one or more sulfonium salts listed in i'-1); vii'-2) one or more thioxanthone compounds listed in i'-2) and one or more iodonium salts listed in i'); vii'-3) one or more anthracene compounds listed in i'-3); vii'-4) one or more naphthalene compounds listed in i'-4) and one or more anthracene compounds listed in i'-4); or vii'-5) comprising one or more coumarin compounds listed in i'-5) and one or more iodonium salts listed in i'); or viii') the mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts listed in iii') and a benzyl ketal compound that is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is viii'-1) one or more sulfonium salts listed in i'-1); viii'-2) one or more thioxanthone compounds listed in i'-2) and one or more iodonium salts listed in i'); viii'-3) one or more anthracene compounds listed in i'-3); viii'-4) one or more naphthalene compounds listed in i'-4) and one or more anthracene compounds listed in i'-4); or viii'-5) comprises one or more coumarin compounds listed in i'-5) and one or more iodonium salts listed in i').

3. 3. The method of claim 1 or 2, wherein the mixture of photoreactive compounds of the radiation-curable coating composition of step a) and the mixture of compounds of the top-curable coating composition of step b) are selected according to one of the following combinations: i″) The mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises The anion portion is SbF ６ － , P.F. ６ － Or (C ６ F ５ ) ４ B － wherein the cationic moiety is one or more iodonium salts which are bis(4-dodecylphenyl)iodonium); bis[4-(1,1-dimethylethyl)phenyl]iodonium; (4-isopropylphenyl)(4-methylphenyl)iodonium; bis(4-methylphenyl)iodonium; (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium; or mixtures thereof; and 2-Hydroxy-2-methylpropiophenone; 2-Hydroxy-4'-hydroxyethoxy-2-methylpropiophenone; 2-Hydroxy-1-[4-[4-(1-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropan-1-one; (1-hydroxycyclohexyl)phenylmethanone; 2-Hydroxy-1-[4-[4-(1-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methyl propan-1-one; 1-[2,3-dihydro-1-[4-(1-hydroxy-2-methyl-1-oxopropyl)phenyl]-1,3,3-trimethyl-1H-inden-5-yl]-2-hydroxy-2-methyl-1-propanone; ar-(1-hydroxy-2-methyl-1-oxopropyl)(1-methylethenyl)-benzene homopolymers, and mixtures thereof; and The mixture of compounds of the top curable coating composition of step b) is i''-1) One or more sulfonium salts selected from the group consisting of tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium hexafluorophosphate, and mixtures thereof; and further 2,4,6-trimethylbenzoyl-ethoxyphenylphosphine oxide; phenyl-bis(2,4,6-trimethylbenzoyl)phosphine one or more acylphosphine compounds selected from the group consisting of bis(1,6-dimethoxybenzoyl)(1,4,4-trimethylpentyl)phosphine oxide; ethyl(3-benzoyl-2,4,6-trimethylbenzoyl)(phenyl)phosphinate; α,α',α''-1,2,3-propanetriyltris[ω-[[phenyl(1,4,6-trimethylbenzoyl)phosphinyl]oxy]-poly(oxy-1,2-ethanediyl), and mixtures thereof; and / or 2-2 one or more glyoxylate compounds selected from the group consisting of 2-oxo-2-phenylacetic acid methyl ester; 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl 2-oxo-2-phenylacetate; and mixtures thereof; and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or 5-[[4-(1-methylethyl)phenyl]thio]-1H-indene-1,2(3H)-dione 2-(O-acetyloxime); 1-[4-( 4-Cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); 1-[9-ethyl-6-(1-methylbenzoyl)-9H-carbazol-3-yl]ethanone-1-(O-acetyloxime); 3-Cyclopentyl-1-[9-ethyl-6-(1-methylbenzoyl)-9H-carbazol-3-yl]-1-propanone-1-(O-acetyloxime);1,8-bis(O-acetyloxime)-1,8-bis[9-(1-ethylhexyl)-6-nitro-9H-carbazol-3-yl]-1,8-octanedione, and mixtures thereof; i'''-2) 2-Isopropyl-9H-thioxanthen-9-one; 4-(1-methylethyl)-9H-thioxanthen-9-one; 1-chloro-4-propoxy-9H-thioxanthen-9-one; 1,3-di[[α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxy]-2,2-bis[[α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxy one or more thioxanthone compounds selected from the group consisting of methylpropane; oligomeric and polymeric compounds thereof, and mixtures thereof, and further one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); i''-3) An anthracene compound which is 9,10-dibutoxy-anthracene, and further comprising one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); i''-4) A naphthalene compound which is 9,10-diethoxy-naphthalene and an anthracene compound which is 9,10-dibutoxy-anthracene, and further comprising one or more acylphosphine compounds listed in i''-1) and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); or i''-5)3-(4-C １０ -C １３ -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one, and further comprising one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); or ii″) the mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises one or more of the iodonium salts listed in i″) and a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is ii''-1) comprises one or more sulfonium salts listed in i''-1); and further one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); ii''-2) One or more thioxanthone compounds listed in i''-2), and further one or more acylphosphine compounds listed in i''-1) and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); ii''-3) One or more anthracene compounds listed in i''-3), and further one or more acylphosphine compounds listed in i''-1) and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); ii''-4) one or more naphthalene compounds listed in i''-4) and one or more anthracene compounds listed in i''-4), and further one or more acylphosphine compounds listed in i''-1) and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); or ii''-5) One or more coumarin compounds listed in i''-5), and further one or more acylphosphine compounds listed in i''-1) and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); iii'') The mixture of photoreactive compounds of the radiation curable coating composition of step a) is selected from the group consisting of diphenyl[4-(phenylthio)phenyl]-sulfonium hexafluoroantimonate; bis[4-(diphenylsulfonium)phenyl]sulfide bishexafluoroantimonate; 4 diphenyl[4-(phenylthio)phenyl]-sulfonium hexafluorophosphate; bis[4-(diphenylsulfonium)phenyl]sulfide bis(hexafluorophosphate); S,S'-(thiodi-4,1-phenylene)bis[S,S'- bis[4-(2-hydroxyethoxy)]phenyl]sulfonium bis[hexafluorophosphate]; S,S'-(thiodi-4,1-phenylene)bis[S,S'-bis[4-(2-hydroxyethoxy)]phenyl]sulfonium bis[hexafluoroantimonate]; 5-[4-(2-hydroxyethoxy)phenyl]thianthrenium hexafluorophosphate, and mixtures thereof, and one or more α-hydroxyketone compounds listed under i''); and The mixture of compounds of the top curable coating composition of step b) is iii''-1) comprises one or more sulfonium salts listed in i''-1), and further one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); iii''-2) one or more thioxanthone compounds listed in i''-2) and one or more iodonium salts listed in i''), and further one or more acylphosphine compounds listed in i''-1) and / or one or more glyoxylate compounds listed in i''-1); and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); iii''-3) One or more anthracene compounds listed in i''-3), and further one or more acylphosphine compounds listed in i''-1) and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); iii''-4) one or more naphthalene compounds listed in i''-4) and one or more anthracene compounds listed in i''-4), and further one or more acylphosphine compounds listed in i'-1) and / or one or more glyoxylate compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); or iii''-5) one or more coumarin compounds listed in i''-5) and one or more iodonium salts listed in i''), and further one or more acylphosphine compounds listed in i''-1) and / or one or more glyoxylate compounds listed in i''-1) and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); or iv″) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts listed in iii″) and a benzyl ketal compound that is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is iv''-1) comprises one or more sulfonium salts listed in i''-1), and further one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); iv''-2) One or more thioxanthone compounds listed in i''-2) and one or more iodonium salts listed in i'), and further one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); iv''-3) One or more anthracene compounds listed in i''-3), and further one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); iv''-4) one or more naphthalene compounds listed in i''-4) and one or more anthracene compounds listed in i''-4), and further one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); or iv''-5) One or more coumarin compounds listed in i''-5) and one or more iodonium salts listed in i''), and further one or more acylphosphine compounds listed in i''-1); and / or one or more glyoxylate compounds listed in i''-1); and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or one or more oxime ester compounds listed in i''-1); or v″) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts listed in i″) and one or more α-hydroxyketone compounds listed in i″); and The mixture of compounds of the top curable coating composition of step b) is v''-1) one or more sulfonium salts listed in i''-1); v''-2) one or more thioxanthone compounds listed in i''-2); v''-3) one or more anthracene compounds listed in i''-3); v''-4) one or more naphthalene compounds listed in i''-4) and one or more anthracene compounds listed in i''-4); or v''-5) containing one or more coumarin compounds listed in i''-5); or vi″) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts listed in i″) and a benzyl ketal compound that is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is vi''-1) one or more sulfonium salts listed under i''-1); vi''-2) one or more thioxanthone compounds listed in i''-2); vi''-3) one or more anthracene compounds listed in i''-3); vi''-4) one or more naphthalene compounds listed in i''-4) and one or more anthracene compounds listed in i''-4); or vi''-5) containing one or more coumarin compounds listed in i''-5); or vii″) the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts listed in iii″) and one or more α-hydroxyketone compounds listed in i″); and The mixture of compounds of the top curable coating composition of step b) is vii''-1) one or more sulfonium salts listed under i''-1); vii''-2) one or more thioxanthone compounds listed in i''-2) and one or more iodonium salts listed in i''); vii″-3) one or more anthracene compounds listed in i″-3); vii''-4) one or more naphthalene compounds listed in i''-4) and one or more anthracene compounds listed in i''-4); or vii''-5) comprising one or more coumarin compounds listed in i''-5) and one or more iodonium salts listed in i''); or viii') the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts listed in iii'') and a benzyl ketal compound that is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is viii''-1) one or more sulfonium salts listed in i''-1); viii''-2) one or more thioxanthone compounds listed in i''-2) and one or more iodonium salts listed in i''); viii″-3) one or more anthracene compounds listed in i″-3); viii''-4) one or more naphthalene compounds listed in i''-4) and one or more anthracene compounds listed in i''-4); or viii''-5) comprises one or more coumarin compounds listed in i''-5) and one or more iodonium salts listed in i'').

4. 4. The method according to claim 1, wherein the mixture of photoreactive compounds of the radiation-curable coating composition of step a) and the mixture of compounds of the top-curable coating composition of step b) are selected according to one of the following combinations: i''') the mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts selected from the group consisting of bis(4-dodecylphenyl)iodonium hexafluoroantimonate; bis(4-methylphenyl)iodonium hexafluorophosphate; (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium hexafluorophosphate, and mixtures thereof (preferably (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium hexafluorophosphate; bis(4-methylphenyl)iodonium hexafluorophosphate, and mixtures thereof); and an α-hydroxyketone compound which is 2-hydroxy-2-methylpropiophenone; and The mixture of compounds of the top curable coating composition of step b) is i'''-1) sulfonium salts which are tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate, and further acylphosphines which are phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or glyoxylate compounds which are 2-2-oxo-2-phenylacetic acid methyl ester; and / or benzil ketal compounds which are 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or oxime ester compounds which are 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); i'''-2) One or more thioxanthone compounds selected from the group consisting of 2-isopropyl-9H-thioxanthen-9-one; 4-(1-methylethyl)-9H-thioxanthen-9-one, and mixtures thereof, and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); i'''-3) An anthracene compound which is 9,10-dibutoxy-anthracene, and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); i'''-4) A naphthalene compound which is 9,10-diethoxy-naphthalene and an anthracene compound which is 9,10-dibutoxy-anthracene, and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or i'''-5)3-(4-C １０ -C １３ coumarin compounds which are phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or 2-2-oxo-2-phenylacetic acid methyl ester; and / or 2,2-dimethoxy-1,2-diphenylethan-1-one benzil ketal compounds; and / or 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime) oxime ester compounds; or ii''') the mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts listed in i''') and a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is ii'''-1) sulfonium salts which are tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate, and further acylphosphines which are phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or glyoxylate compounds which are 2-2-oxo-2-phenylacetic acid methyl ester; and / or benzil ketal compounds which are 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or oxime ester compounds which are 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); ii'''-2) One or more thioxanthone compounds listed in i'''-2), and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); ii'''-3) An anthracene compound which is 9,10-dibutoxy-anthracene, and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); ii'''-4) A naphthalene compound which is 9,10-diethoxy-naphthalene and an anthracene compound which is 9,10-dibutoxy-anthracene, and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or ii'''-5) 3-(4-C １０ -C １３ coumarin compounds which are phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or glyoxylate compounds which are 2-2-oxo-2-phenylacetic acid methyl ester; and / or benzil ketal compounds which are 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or oxime ester compounds which are 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or iii''') the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts selected from the group consisting of diphenyl[4-(phenylthio)phenyl]-sulfonium hexafluoroantimonate; (thiodi-4,1-phenylene)bis[diphenyl-sulfonium bis-hexafluoroantimonate; and mixtures thereof, and one or more α-hydroxyketone compounds listed in i'''); and The mixture of compounds of the top curable coating composition of step b) is iii'''1) sulfonium salts which are tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate, and further including acylphosphines which are phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or glyoxylate compounds which are 2-2-oxo-2-phenylacetic acid methyl ester; and / or benzil ketal compounds which are 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or oxime ester compounds which are 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iii'''-2) One or more thioxanthone compounds listed in i'''-2) and one or more iodonium salts listed in i'''), and further comprising an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iii'''-3) An anthracene compound which is 9,10-dibutoxy-anthracene, and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iii'''-4) A naphthalene compound which is 9,10-diethoxy-naphthalene and an anthracene compound which is 9,10-dibutoxy-anthracene, and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or iii'''-5) 3-(4-C １０ -C １３ -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one and one or more of the iodonium salts listed in i'''), and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or iv''') the mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts listed in iii''') and a benzyl ketal compound that is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is iv'''-1) sulfonium salts which are tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate, and further including acylphosphines which are phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or glyoxylate compounds which are 2-2-oxo-2-phenylacetic acid methyl ester; and / or benzil ketal compounds which are 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or oxime ester compounds which are 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iv'''-2) One or more thioxanthone compounds listed in i'''-2) and one or more iodonium salts listed in i'''), and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iv'''-3) An anthracene compound which is 9,10-dibutoxy-anthracene, and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iv'''-4) A naphthalene compound which is 9,10-diethoxy-naphthalene and an anthracene compound which is 9,10-dibutoxy-anthracene, and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or iv'''-5) 3-(4-C １０ -C １３ -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one and one or more of the iodonium salts listed in i'''), and further including an acylphosphine which is phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or a glyoxylate compound which is 2-2-oxo-2-phenylacetic acid methyl ester; and / or a benzil ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and / or an oxime ester compound which is 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or v''') the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more iodonium salts listed in i''') and one or more α-hydroxyketone compounds listed in i'''); and The mixture of compounds of the top curable coating composition of step b) is v'''-1) a sulfonium salt which is tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate; v'''-2) one or more thioxanthone compounds listed in i'''-2); v'''-3) an anthracene compound which is 9,10-dibutoxyanthracene; v'''-4) a naphthalene compound which is 9,10-diethoxy-naphthalene and an anthracene compound which is 9,10-dibutoxy-anthracene; or v'''-5)3-(4-C １０ -C １３ -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one; or vi''') the mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts listed in i''') and a benzyl ketal compound that is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is vi'''-1) a sulfonium salt which is tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate; vi'''-2) one or more thioxanthone compounds listed in i'''-2); vi'''-3) an anthracene compound which is 9,10-dibutoxy-anthracene; vi'''-4) a naphthalene compound which is 9,10-diethoxy-naphthalene and an anthracene compound which is 9,10-dibutoxy-anthracene; or vi'''-5) 3-(4-C １０ -C １３ -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one; or vii''') the mixture of photoreactive compounds of the radiation-curable coating composition of step a) comprises one or more sulfonium salts listed in iii''') and one or more α-hydroxyketone compounds listed in i'''); and The mixture of compounds of the top curable coating composition of step b) is vii'''-1) a sulfonium salt which is tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate; vii'''-2) one or more thioxanthone compounds listed in i'''-2) and one or more iodonium salts listed in i'''); vii'''-3) an anthracene compound which is 9,10-dibutoxy-anthracene; vii'''-4) a naphthalene compound which is 9,10-diethoxy-naphthalene and an anthracene compound which is 9,10-dibutoxy-anthracene; or vii'''-5) 3-(4-C １０ -C １３ -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one and one or more of the iodonium salts listed under i'''); or viii''') the mixture of photoreactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts listed in iii''') and a benzyl ketal compound which is 2,2-dimethoxy-1,2-diphenylethan-1-one; and The mixture of compounds of the top curable coating composition of step b) is viii'''-1) a sulfonium salt which is tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate; viii'''-2) one or more thioxanthone compounds listed in i'''-2) and one or more iodonium salts listed in i'''); viii'''-3) an anthracene compound which is 9,10-dibutoxy-anthracene; viii'''-4) A naphthalene compound which is 9,10-diethoxy-naphthalene and an anthracene compound which is 9,10-dibutoxy-anthracene; or viii'''-5) 3-(4-C １０ -C １３ -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one and one or more of the iodonium salts listed under i''').

5. the mixture i), i'), i"), i'"), ii), ii'), ii"), ii'"), v), v'), v"), v'"), vi), vi'), vi") or vi'") comprises one or more thioxanthone compounds, said mixture further comprising one or more iodonium salts listed in any one of i), i'), i") or i'"); and / or Mixture i), i'), i''), i'''), ii), ii'), ii''), ii'''), iii), iii'), iii''), iii'''), iv), iv'), iv''), iv'''), v ), v'), v''), v'''), vi), vi'), vi''), vi'''), vii, vii'), vii''), vii'''), viii), viii'), viii'') or viii'' ') comprises one or more anthracene compounds, said mixture further comprising one or more iodonium salts listed in any one of i), i'), i"), or i'''), and / or one or more sulfonium salts listed in any one of i-1), i'-1), i"-1), i'''-1), iii), iii'), iii"), or iii'''); and / or Mixture i), i'), i''), i'''), ii), ii'), ii''), ii'''), iii), iii'), iii''), iii'''), iv), iv'), iv''), iv'''), v), v' ), v''), v'''), vi), vi'), vi''), vi'''), vii), vii'), vii''), vii'''), viii), viii'), viii'') or viii''') are one or comprises a plurality of naphthalene compounds and one or more anthracene compounds, said mixture further comprising one or more iodonium salts listed in any one of i), i'), i"), or i'"), and / or one or more sulfonium salts listed in any one of i-1), i'-1), i"-1), i'"-1), iii), iii'), iii"), or iii'"); and / or 5. The method of any one of claims 1 to 4, wherein the mixture i), i'), i"), i'"), ii), ii'), ii"), ii'"), v), v'), v"), v'"), vi), vi'), vi") or vi'") comprises one or more coumarin compounds, and said mixture further comprises one or more iodonium salts listed in any one of i), i'), i") or i'").

6. 6. The method according to claim 1, further comprising the step of exposing the coating layer (x10) to a magnetic field of a magnetic field generating device in order to orient at least a portion of the magnetic or magnetizable pigment particles, said step being carried out after or partially simultaneously with step b) and before step c).

7. 7. The method according to any one of claims 1 to 6, further comprising the step of exposing the coating layer (x10) to a magnetic field of a magnetic field generating device in order to orient at least a portion of the magnetic or magnetizable pigment particles, said step being carried out after step a) and before step b).

8. 8. The method according to any one of claims 1 to 7, wherein the step d) of exposing the coating layer (x10) and / or the step of exposing the coating layer (x10) to a magnetic field of a magnetic field generating device of claim 6 or 7 is carried out in order to uniaxially orient at least a portion of the non-spherical magnetic or magnetisable pigment particles.

9. 9. The method according to any one of claims 1 to 8, wherein the step d) of exposing the coating layer (x10) and / or the step of exposing the coating layer (x10) to the magnetic field of a magnetic field generating device of claim 6 or 7 is carried out in order to biaxially orient at least a portion of the non-spherical magnetic or magnetizable pigment particles, the non-spherical magnetic or magnetizable pigment particles being platelet-shaped magnetic or magnetizable pigment particles, with an X-axis and a Y-axis defining the main planes of extension of the particles.

10. 10. The method according to claim 9, wherein said step d) of exposing said coating layer (x10) is carried out to biaxially orient at least a portion of said platelet-shaped magnetic or magnetizable pigment particles with both their X-axis and Y-axis substantially parallel to the substrate surface.

11. 8. The method according to claim 1, wherein the step of exposing the coating layer (x10) to the magnetic field of a magnetic field generator of step d) and / or claim 6 or 7 comprises two steps: a first step of exposing the coating layer (x10) to the magnetic field of a magnetic field generator in order to orient at least a portion of the platelet-shaped magnetic or magnetizable pigment particles biaxially, and a second step of exposing the coating layer (x10) to the magnetic field of a second magnetic field generator in order to orient at least a portion of the platelet-shaped magnetic or magnetizable particles uniaxially, said second step being carried out partially simultaneously with, simultaneously with or after the first step.

12. 12. The method according to any one of claims 1 to 11, wherein step a) of applying the radiation curable coating composition is carried out by a process selected from the group consisting of screen printing, gravure printing, pad printing and flexographic printing, and / or step b) of applying the top coating composition is carried out by a non-contact fluid micro-dispensing technique, preferably an inkjet printing process.

13. 13. The method according to any one of claims 1 to 12, wherein at least a part of said non-spherical magnetic or magnetisable particles are constituted by non-spherical optically variable magnetic or magnetisable pigment particles.

14. 14. The method of claim 13, wherein the non-spherical optically variable magnetic or magnetizable pigment particles are selected from the group consisting of magnetic thin film interference pigments, magnetic cholesteric liquid crystal pigments, and mixtures thereof.

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